C1 English & TOEFL 100+ Cheatsheet

Personalized to your assessment profile. Covers every grammar area for C1, your exact gap patterns, and a complete guide to achieving TOEFL 100+ in Writing and Speaking.

Missing auxiliaries Verb forms Articles Tense consistency Subject-verb agreement Connector errors TOEFL Writing 24+ TOEFL Speaking 24+
A

Your Gap Analysis — Where You Are vs. Where You Need to Be

SkillYour Current LevelTarget (TOEFL 100+)Gap
ReadingAdvanced / C1+Advanced / C1+✓ No gap
ListeningAdvanced / C1+Advanced / C1+✓ No gap
VocabularyAbove averageC1 range★ See Section 14
SpeakingUpper-intermediateC1 / TOEFL 24+★ Grammar stability under pressure
WritingIntermediateC1 / TOEFL 24+★ Tense, auxiliaries, articles, structure

Your 6 exact mistake patterns

#Error type✗ Wrong✓ CorrectRule
#1Missing auxiliary verbI currently looking for a new role.I am currently looking for a new role.am/is/are before every -ing verb
#2Wrong verb formThe company has grew rapidly.The company has grown rapidly.has/have + past participle
#3Missing articleI work in technology industry.I work in the technology industry.Specific/known noun → the
#4Subject-verb agreementEach employee have responsibilities.Each employee has responsibilities.each/every = singular verb
#5Connector errorAlthough AI is useful, but it has risks.Although AI is useful, it has risks.One connector per clause only
#6Tense inconsistencyI joined in 2020 and work on AI.I joined in 2020 and worked on AI.Choose a tense and stay in it
Your cognitive pattern: You think ideas first, grammar second. Under pressure, sentence structure collapses. The fix is not memorising more rules — it is slowing down 10% and completing every sentence before starting the next one.
1

Auxiliary Verbs — Your #1 Priority

1.1 BE — continuous & passive

UseForm✓ CorrectCommon mistake
Present continuousam/is/are + -ingI am working on a new product.I currently working
Past continuouswas/were + -ingShe was leading the team.She leading the team
Future continuouswill be + -ingWe will be presenting tomorrow.We will presenting
Present passiveis/are + ppThe code is reviewed daily.The code reviewed
Past passivewas/were + ppThe report was written last week.The report written

1.2 DO — negatives & questions

UseForm✓ CorrectCommon mistake
Present negativedo/does not + baseI do not agree with that.I not agree
Past negativedid not + baseShe did not finish on time.She not finished
Present questionDo/Does + S + base?Does this affect the timeline?This affect the timeline?
Past questionDid + S + base?Did you review the pull request?You reviewed the pull request?

1.3 HAVE — perfect tenses

UseForm✓ CorrectCommon mistake
Present perfecthas/have + ppWe have launched three times.We launched (unspecified)
Past perfecthad + ppBy launch, we had tested everything.By launch, we tested
Present perf. cont.has/have been + -ingThe team has been working hard.The team been working
2

All 12 Verb Tenses — Complete Reference Tables

2.1 Present tenses

TenseFormExample 1Example 2When to useNegative
Simple presentbase / base+sI work in AI.She works here every day.Habits, facts, routinesdo/does not + base
Present continuousam/is/are + -ingI am working on this now.I am meeting the client tomorrow.Action in progress NOW; fixed future planam/is/are not + -ing
Present perfecthas/have + ppI have worked here for 3 years.She has just sent the email.Past action connected to now; life experiencehas/have not + pp
Present perfect cont.has/have been + -ingI have been working since 9am.They have been building this for months.Ongoing action from past to now; durationhas/have not been + -ing

2.2 Past tenses

TenseFormExample 1Example 2When to useNegative
Simple pastverb-ed / irregularWe launched in 2021.She wrote the report yesterday.Completed action at a specific past timedid not + base
Past continuouswas/were + -ingI was working when she called.They were testing all night.Action in progress at a past moment; interrupted actionwas/were not + -ing
Past perfecthad + ppWe had shipped before the update.By 2020, she had led three teams.Action completed BEFORE another past actionhad not + pp
Past perfect cont.had been + -ingWe had been testing for days before the fix.She had been waiting for an hour.Ongoing past action before another past eventhad not been + -ing

2.3 Future tenses

TenseFormExample 1Example 2When to useNegative
will + basewill + baseI will present the results.It will probably rain.Spontaneous decision; prediction; promisewill not (won't) + base
be going toam/is/are going to + baseWe are going to expand next year.It's going to rain — look at those clouds.Pre-made plan; evidence-based predictionam/is/are not going to + base
Future continuouswill be + -ingI will be presenting at 10am.They will be travelling all week.Action in progress at a specific future momentwill not be + -ing
Future perfectwill have + ppI will have finished by Friday.By 2030, AI will have transformed healthcare.Action completed before a specific future pointwill not have + pp
Future perfect cont.will have been + -ingBy June, I will have been working here for 5 years.She will have been leading the project for a year.Duration of ongoing action up to a future pointwill not have been + -ing

2.4 Tense consistency — your TOEFL risk

Issue✗ Wrong✓ Correct
Past → present shiftI joined in 2020 and work on the AI team.I joined in 2020 and worked on the AI team.
Unnecessary shiftThe report was clear. It shows the key findings.The report was clear. It showed the key findings.
Acceptable shiftI worked there for years. Now I run my own company. ✓ (time genuinely changes)
TOEFL tip: Decide tense in sentence 1. Use present for general arguments. Use past for specific examples. Never switch without a reason.
3

Irregular Verbs — 36 High-Frequency Forms

Your profile error: "has grew" → must be "has grown". After has/have always use the past participle (3rd column), never past simple (2nd column).
BasePast simplePast participleBasePast simplePast participle
arisearosearisenovercomeovercameovercome
bearboreborneriseroserisen
beatbeatbeatenrunranrun
beginbeganbegunseeksoughtsought
breakbrokebrokenshowshowedshown
buildbuiltbuiltspeakspokespoken
choosechosechosenstealstolestolen
drivedrovedrivenstrivestrovestriven
fallfellfallentaketooktaken
forgetforgotforgottenthrowthrewthrown
grow ★your errorgrewgrownwearworeworn
hidehidhiddenwithdrawwithdrewwithdrawn
keepkeptkeptwritewrotewritten
laylaidlaidfindfoundfound
leadledledholdheldheld
loselostlostknowknewknown
drawdrewdrawnmeanmeantmeant
dealdealtdealtcomecamecome
4

Articles — a / an / the / Ø

ArticleRuleExamples
THE Both speaker & listener know which one. Specific, unique, or previously mentioned. I work in the technology industry.
She is the CEO of the company.
The report we discussed is ready.
The internet changed everything.
A / AN First mention OR non-specific. Use A before consonant sounds, AN before vowel sounds. She is a CEO I met at a conference.
We need an efficient solution.
He is an engineer. ✓ (NOT: a engineer)
Ø Languages, most countries, meals, subjects, by + transport, uncountable nouns (general use), plural nouns (general). Ø English is difficult. (languages)
She studies Ø engineering. (subjects)
I had Ø lunch. / by Ø car, by Ø train
Ø information, Ø advice, Ø feedback
Indonesian has no articles — check every noun. Ask: specific/known? → the. First mention/general? → a/an. Uncountable/plural-general? → Ø
5

Subject–Verb Agreement

Pattern✓ CorrectFix
each / every / either / neither + singular nounEach employee has responsibilities.have → has
one of the + plural nounOne of the options is better.are → is
the number of + plural nounThe number of users is growing.are → is
a number of + plural nounA number of users are affected.is → are
there is / there areThere are three main challenges.there is problems → there are
either…or / neither…norNeither the CEO nor the staff is informed.verb agrees with nearer subject
uncountable nounsThe information is accurate.informations are → information is
who/which/that relative clauseIt is the engineers who are responsible.who is → who are
6

Connectors & Linkers — C1 Level

Your profile error: "Although AI is useful, but it has risks." — WRONG. Never use two connectors for one relationship. Choose one.
FunctionConnectorFollowed byExample
Contrastalthough / even thoughclauseAlthough the project was delayed, the quality was high.
Contrasthowever / neverthelessnew sentenceThe costs were high. However, the ROI justified it.
Contrastdespite / in spite ofnoun / -ingDespite the challenges, we delivered on time.
Contrastwhereas / whiletwo clausesHe prefers remote work, whereas she likes the office.
Causebecause / since / asclauseSince the budget was cut, we reprioritised.
Causedue to / owing tonoun / -ingDue to high demand, we scaled the servers.
Resulttherefore / consequentlynew sentenceThe API was slow; consequently, users dropped off.
Additionfurthermore / moreovernew sentenceFurthermore, the data supports this hypothesis.
Additionin addition tonoun / -ingIn addition to the report, she prepared a summary.
Conditionprovided that / as long asclauseProvided that we stay on budget, we can proceed.
Concessionadmittedly / grantednew sentenceAdmittedly, the approach has flaws.
Purposeso as to / in order toinfinitiveWe automated this so as to reduce errors.
Clarificationthat is / namelyphraseOne issue, namely the latency, was unresolved.
7

Conditionals — Zero to Mixed + Formal Inversions

TypeIF clauseMain clauseExampleUse
Zeropresent simplepresent simpleIf you heat water to 100°C, it boils.General truths, facts
Firstpresent simplewill + baseIf we launch this week, we will hit the target.Real future possibility
Secondpast simplewould + baseIf I had more time, I would rewrite the code.Hypothetical present/future
Thirdpast perfectwould have + ppIf we had tested earlier, we would have caught the bug.Hypothetical past
Mixedpast perfectwould + baseIf she had studied CS, she would be a developer now.Past condition, present result

Formal inversions — C1 signal to examiners

Formal sentenceSource
Were I to start over, I would choose a different approach.Inversion of 2nd conditional
Had we known about the issue, we would have resolved it sooner.Inversion of 3rd conditional
Should you need further information, please contact me.Inversion of 1st conditional
Unless we automate this, costs will continue to rise.= if not
9

Passive Voice — All Tenses

TenseFormExample
Simple presentis/are + ppData is processed automatically.
Present continuousis/are being + ppThe system is being updated.
Present perfecthas/have been + ppThe error has been resolved.
Simple pastwas/were + ppThe report was submitted yesterday.
Past continuouswas/were being + ppThe code was being reviewed when the issue occurred.
Past perfecthad been + ppThe contract had been signed before the launch.
Simple futurewill be + ppResults will be published next week.
Future perfectwill have been + ppThe project will have been completed by then.
Modal passivemodal + be + ppThis should be tested. / It must be approved.
Modal perf. passivemodal + have been + ppIt should have been documented.
The report written by the team. (missing was)
The report was written by the team.
The system is being update.
The system is being updated.
10

Reported Speech — Tense Backshift Table

Direct tenseReported tenseExample
present simplepast simple"I work here." → She said she worked there.
present continuouspast continuous"I am working." → He said he was working.
present perfectpast perfect"I have finished." → She said she had finished.
past simplepast perfect"I sent it." → He said he had sent it.
willwould"I will call." → She said she would call.
cancould"I can help." → He said he could help.
musthad to"You must sign." → She said I had to sign.
maymight"It may work." → He said it might work.
is going towas going to"We are going to launch." → She said they were going to launch.
No backshift needed when reporting immediately / information still true / using: believe, suppose, feel, think, know, hope.
11

Gerund vs Infinitive — Patterns & Meaning Changes

Verbs + gerund (-ing)

admit · avoid · consider · delay · deny · enjoy · finish · imagine · involve · keep · mention · mind · miss · postpone · practise · recommend · risk · suggest

Verbs + infinitive (to + base)

afford · agree · aim · appear · arrange · attempt · choose · decide · demand · expect · fail · hesitate · hope · intend · manage · offer · plan · promise · refuse · seem · tend · threaten · want · wish

Verbs with meaning change — C1 exam favourite

VerbFormMeaningExample
remember+ -ingrecall a past eventI remember sending the email last week.
+ to-infdon't forget to doRemember to send the email before 5pm.
stop+ -ingquit an activityWe stopped testing the feature.
+ to-infpause in order to doWe stopped to test the feature.
try+ -ingexperiment / attempt a solutionTry using a different framework.
+ to-infmake an effort (may fail)I tried to fix it but couldn't.
mean+ -inginvolve / entailScaling means investing more.
+ to-infintendI didn't mean to interrupt.
regret+ -ingsorry about a past actionI regret saying that.
+ to-infformal bad newsWe regret to inform you that…
12

Countable / Uncountable & Prepositions

Noun✗ Wrong✓ Correct
informationan information / informationssome information / a piece of information
adviceadvices / an advicesome advice / a piece of advice
feedbackfeedbackssome feedback / a lot of feedback
researcha research / researchessome research / a research study
equipmentequipmentssome equipment / a piece of equipment
progressa progresssignificant progress / make progress
newsa news (always singular verb!)some news / the latest news
workworks (= artworks only)some work / a lot of work

High-frequency preposition collocations

Phrase✓ CorrectNote
responsible forShe is responsible for the product.NOT: responsible of
interested inI am interested in machine learning.NOT: interested on
aware ofBe aware of the risks.NOT: aware about
capable ofShe is capable of leading the team.NOT: capable to
result inThis will result in delays.NOT: result on/at
rely on / depend onWe rely on real-time data.NOT: rely in
differ fromThis approach differs from the original.NOT: differ with/to
on time vs in timeSubmit on time. / Finish in time to review.on time = punctual; in time = before deadline
13

C1 Sentence Structures — Advanced Forms

Cleft sentences — for emphasis

It was the latency that caused the issue. (not: The latency caused the issue.)
What we need is better documentation.
It is their work ethic that sets them apart.

Fronting & inversion

Inverted sentenceRule
Not only did we reduce costs, but we also improved quality.not only…but also → inverted first clause
Rarely have I seen such rapid growth.adverb of frequency at front → inversion
Only after the meeting did we realise the full scope.only + time phrase → inversion
Under no circumstances should you share the credentials.negative phrase at front → inversion
So complex was the problem that it required three engineers.so + adjective at front → inversion

Participle clauses

Having reviewed the data, I recommend a different approach. (= After I had reviewed…)
Built on a microservices architecture, the system scales efficiently.
Not knowing the full context, she made an uninformed decision.
14

C1 Vocabulary — Academic & Professional

VerbExample sentence
argueI would argue that automation increases inequality.
assertThe report asserts that remote work improves productivity.
contendCritics contend that the policy is insufficient.
attribute toThe success can be attributed to strong leadership.
demonstrateThe data demonstrates a clear correlation.
implyThe results imply that our model needs retraining.
indicatePreliminary data indicates a positive trend.
substantiateAdditional evidence is needed to substantiate the claim.
undermineThis finding undermines the original hypothesis.

Formal phrases for TOEFL writing

PhraseExample
It is widely acknowledged that…It is widely acknowledged that AI presents ethical challenges.
A growing body of evidence suggests…A growing body of evidence suggests that remote work is productive.
This raises the question of…This raises the question of how we define accountability.
It would be reasonable to conclude…It would be reasonable to conclude that costs will rise.
In light of…In light of recent findings, we should reconsider the approach.
One could argue that…One could argue that the benefits outweigh the risks.
To a certain extent,…To a certain extent, both arguments have merit.
With this in mind,…With this in mind, we propose a phased rollout.
B

TOEFL 100+ — Score Structure & What You Need

Reading
0–30
Listening
0–30
Speaking
0–30
Writing
0–30
Total
0–120
SectionScaleTargetWhat this requiresPriority
Reading0–3026+Already at this level. Maintain.✓ Strong
Listening0–3026+Already at this level. Maintain.✓ Strong
Speaking0–3024+Grammar stability under pressure + delivery + structure★ Focus area
Writing0–3024+Tense consistency, auxiliaries, articles, sentence control★ Focus area
Reading + Listening ≈ 52+ likely based on your profile. Writing 24 + Speaking 24 = 48. Total ≈ 100+. Every point in Writing and Speaking comes from grammar control and structure.
15

TOEFL Writing — Task 1 (Integrated) Full Guide

Read passage
3 min
Listen to lecture
~2–3 min
Write response
20 min
Target word count
150–225
The lecture always contradicts or challenges the reading. Your job: summarise how the lecture challenges each reading point. Never add your own opinion.

Scoring rubric

ScoreWhat the rater looks for
5Accurately reports ALL key lecture points. Clearly relates each to the reading. Well-organised. Precise language. Minor errors only.
4Covers all key points but may be slightly less precise. Organisation clear. Some minor errors that don't obscure meaning.
3Covers key points but with some inaccuracy or omission. Some grammar/vocab errors that occasionally obscure meaning.
2Important lecture points missing or inaccurate. Limited connection to reading. Frequent grammar errors.
1Minimal relevant content. Serious and frequent grammar errors throughout.

Template — fill in from your notes

Opening (2 sentences)
The reading passage argues that [main claim about topic]. However, the professor's lecture challenges this view by presenting three counterarguments.
Point 1 (3–4 sentences)
First, while the reading claims that [X], the lecturer contends that [Y]. Specifically, [detail from lecture]. This directly contradicts the reading's assertion that [restate reading point].
Point 2 (3–4 sentences)
Second, the reading asserts that [X]. The lecturer, however, argues that [Y], pointing out that [evidence from lecture]. The professor suggests that [conclusion from this point].
Point 3 (3–4 sentences)
Finally, the reading suggests that [X]. The lecturer disputes this by explaining that [Y]. According to the professor, [supporting detail].
Closing (1 sentence)
In summary, the lecturer effectively challenges each of the three points raised in the reading passage.
Attribution phrases to use: "the lecturer argues…", "the professor points out…", "according to the lecture…", "the speaker contends…", "the professor disputes this by…"
16

TOEFL Writing — Task 2 (Academic Discussion) Full Guide

Task 2 replaced the old Independent Essay in 2023. You see a professor's question and two student responses. Add your own opinion. Target: 100+ words, ideally 150–200.

Read posts
~2 min
Plan
1–2 min
Write response
8–10 min
Target words
100–200

Scoring rubric

ScoreWhat the rater looks for
5Contributes meaningfully to discussion. Clearly states and defends a position. Relevant reasons and examples. Well-organised. Effective vocabulary. Mostly accurate grammar.
4Relevant contribution. Position clear. Some development. Minor errors that do not impede communication.
3Relevant but limited development. Some unclear reasoning. Some grammar/vocabulary errors.
2Contribution is vague or off-topic. Limited development. Frequent errors.
1Does not contribute meaningfully. Pervasive errors.

Template

Sentence 1 — your position
I agree with [student name]'s point that [their main idea], and I would like to add that [your main idea].
Sentences 2–3 — your reason
In my view, [reason]. For example, [specific example — ideally from your own professional experience].
Sentence 4 — respond to the other student
While [second student] raises a valid point about [their idea], I think [your counterpoint or extension of the idea].
Sentence 5 — closing
Ultimately, [restate your position briefly and connect to the broader topic].
Your risk: starting sentence 2 with a complex structure before finishing sentence 1. Write short, complete sentences first. Add complexity only when you are certain the base sentence is grammatically correct.
17–18

TOEFL Speaking — All 4 Tasks + Scoring Rubric

Task 1 — Independent (personal opinion)

Prep
15s
Speak
45s
Source
Your personal opinion only
Sentence 1 (0–5s)
I believe that [position] because it [core reason].
Sentences 2–3 (5–20s)
For example, [specific example from work or life]. This shows that [result / impact].
Sentence 4 (20–35s)
Moreover, [second reason]. In contrast, [opposing view] does not account for [factor].
Sentence 5 (35–45s)
For these reasons, I think [restate position briefly].

Task 2 — Integrated: campus situation (reading + conversation)

Prep
30s
Speak
60s
Source
Announcement + student conversation
Intro (0–10s)
The reading announces that [main change/plan].
Opinion (10–20s)
The [man/woman] [agrees/disagrees] with this. He/She thinks that [overall view].
Reason 1 (20–40s)
First, he/she argues that [reason 1]. Specifically, [detail from conversation].
Reason 2 (40–60s)
Second, he/she points out that [reason 2]. According to him/her, [supporting detail].

Task 3 — Integrated: academic concept (reading + lecture)

Prep
30s
Speak
60s
Source
Short text defining concept + lecture example
Intro (0–10s)
The reading describes [concept] as [brief definition in 1 sentence].
Lecture link (10–20s)
The professor illustrates this with the example of [topic of example].
Detail 1 (20–40s)
According to the lecture, [first key detail]. This relates to the concept because [connection].
Detail 2 (40–60s)
The professor also explains that [second detail]. This further demonstrates [concept].

Task 4 — Integrated: academic lecture only

Prep
20s
Speak
60s
Source
Lecture only — no reading
Intro (0–10s)
The professor discusses [concept / topic of lecture].
Point 1 (10–30s)
First, the professor explains that [main point 1]. For example, [detail from lecture].
Point 2 (30–55s)
Second, the professor describes [main point 2]. According to the lecture, [detail].
Closing (55–60s)
Both examples illustrate [the main concept / the overall argument].

Speaking scoring rubric — 3 dimensions, 0–4 per task

DimensionWhat it measures4 (top score)Your risk
DeliveryPace, clarity, pronunciation, natural flowFluid, clear, minor hesitation onlyRushing → incomplete sentences
Language useGrammar range, accuracy, vocabularyEffective structures, minor errors onlyAuxiliary missing, tense collapse
Topic developmentContent completeness, coherence, relevanceFully addresses task, well-organisedStrong — your ideas are clear
Your specific speaking risk: grammar collapses mid-sentence under time pressure. Use shorter, grammatically complete sentences. A short correct answer scores higher than a long incorrect one.
19

Production Under Pressure — Your Specific Strategy

Writing strategy under time pressure

#StrategyHow to apply it
1Decide tense in sentence 1Choose present (for arguments) or past (for examples). Stick to it for the whole paragraph.
2One sentence at a timeStop at the full stop. Before moving on: is there a subject? a verb? an article on every specific noun?
3Start with Subject + VerbDon't open with a subordinate clause if you're under pressure. "The system improves efficiency because…" beats "Although there are many factors, the system…"
4Shorter beats longer"The company has grown rapidly." scores higher than an unfinished complex sentence every time.
53-second auxiliary checkBefore every -ing verb: did I write am/is/are/was/were? Before every pp after has/have: is it the right form?
62-second article checkEvery new specific noun: does it need "the"? Is it uncountable? → no article.

Speaking strategy under time pressure

#StrategyHow to apply it
1Use prep time to plan sentences, not topicsIn 15–30 seconds, plan the sentence structure: S + V + Object. Not just the idea.
245 seconds = 5 short sentencesOne sentence per ~9 seconds. Each: Subject → Verb → Object/Complement. Complete every sentence.
3Never start a sentence you can't finishIf you can't see the end of the sentence, use a simpler structure instead.
4Use linking phrases to buy thinking time"That's an interesting point because…", "What this means is…", "To give an example…"
5Recover fast from errorsIf you make a grammar error, don't pause to self-correct. Finish the sentence, move on.
6Signal structure to the rater"My second reason is…" / "The lecture also mentions…" — clear signalling adds to your score.
20

Pre-Submission Checklist — Run This Every Time

  • 1Auxiliary verbsam/is/are before every -ing? do/does/did before negatives/questions?I am working ✓
  • 2Verb formsPast participle (not past simple) after has/have?has grown ✓
  • 3ArticlesEvery noun: specific → the. First mention → a/an. Uncountable → Øthe industry ✓
  • 4Subject-verbDoes verb match grammatical subject (not nearest noun)?each has ✓
  • 5TenseSame tense throughout paragraph? No unintended shifts?joined + worked ✓
  • 6ConnectorsOne connector per clause? No "although…but"?although X, Y ✓
  • 7SentencesEvery sentence has subject + verb + full stop?complete ✓
  • 8Modal pastPast deductions: modal + have + pp?must have caused ✓
  • 9UncountableNo plural -s on information/advice/feedback/research?some feedback ✓
  • 10Prepositionsresponsible FOR, interested IN, result IN, rely ON, differ FROM?responsible for ✓
21

7-Day Practice Plan — 20 Minutes/Day

Mon
Grammar drills
5 auxiliary + 5 verb form MCQ. Review every explanation.
Tue
Writing feedback
Write 3 paragraphs. Run AI feedback. Note repeated mistakes.
Wed
Speaking tasks
3 × TOEFL tasks with timer. Record yourself. Check checklist.
Thu
Vocabulary
5 words from Section 14. Write 2 sentences per word.
Fri
Full Task 1
One TOEFL Writing Task 1 (20 min). Run checklist. Focus on tense.
Sat
Verb sprint
Cover column 3 of Section 3. Write all 36 past participles from memory.
Sun
Mock test
Writing Task 2 + 2 Speaking tasks under timed conditions. Self-score with rubric.
Assessment: With consistent daily practice targeting Sections 1–6 (grammar gaps) and Sections 15–19 (TOEFL writing/speaking), you are likely capable of achieving TOEFL 100+ in 6–10 weeks. Your comprehension and vocabulary are already there — this is purely a production exercise.

Estimated trajectory: Week 1–2: grammar errors drop 50%. Week 3–4: writing score reaches 21–22. Week 5–6: writing 23–24, speaking 22–23. Week 7–10: TOEFL 100+ readiness.