19 topics
Grammar and punctuation, explained by the rule underneath
Almost every comma rule in English is really one question wearing different hats: is the thing on each side of this mark a complete sentence or not? Once you can tell an independent clause from a dependent one in about two seconds, the comma splice, the semicolon, the run-on and the sentence fragment all collapse into a single decision you make the same way every time.
Where students get stuck
My essay keeps coming back marked CS or run-on
CS means comma splice: you joined two complete sentences with only a comma. Test it by covering each side of the comma and asking whether that half could stand alone with a full stop. If both halves can, a comma alone is not strong enough. You have four legal repairs: a full stop, a semicolon, a comma plus one of the seven coordinating conjunctions (for, and, nor, but, or, yet, so), or turning one half into a dependent clause by opening it with a word like because or although.
I never know when to use a semicolon
A semicolon does exactly one common job: it joins two complete sentences that are closely related, where a full stop would feel too final. If either side cannot stand alone, you want a comma or nothing at all. The trap is words like however, therefore and moreover. Those are not conjunctions, so writing it rained, however we played splices two sentences. It needs a semicolon before however and a comma after it. The other semicolon job is separating list items that already contain commas.
Its or it’s, and where the apostrophe goes in plurals
It’s is only ever the contraction of it is or it has. Its, with no apostrophe, is possessive, exactly like his and hers, which nobody writes with apostrophes either. For nouns, decide the plural first, then add the apostrophe. One student, so student’s essay. Several students, so students’ essays. The apostrophe never makes something plural, which is why a sign advertising apple’s is wrong. Names ending in s follow the same order: James, then James’s or James’ depending on your style guide.
The modifier at the front of my sentence is marked wrong
That is a dangling or misplaced modifier. An opening phrase attaches itself to whatever noun comes immediately after the comma, whether you meant it to or not. Walking to school, the rain started writes that the rain was walking. Fix it by naming the real actor first: walking to school, I got caught in the rain. Only, just and almost cause the same trouble mid-sentence, because they modify whatever follows them. I only ate two slices and I ate only two slices mean different things.
Subject-verb agreement when the sentence is long
The verb agrees with the subject, not with the nearest noun. In the box of samples was delivered, the subject is box, not samples, so the singular verb is right even though it sounds odd out loud. Cross out every prepositional phrase and the true subject is what remains. Each, every, everyone, neither and either are singular no matter how plural they feel. Compound subjects joined by and are plural, but joined by or the verb matches the part nearest to it.
What's covered
Grammar & Punctuation topics you can work through with a tutor, generate practice on, or turn into flashcards and a study plan.
Sentence structure
- Independent and dependent clauses
- Simple, compound, complex and compound-complex sentences
- Fragments, run-ons and comma splices
- Coordinating and subordinating conjunctions
- Parallel structure in lists and comparisons
Punctuation
- Commas in lists, after introductory phrases and around interrupters
- Semicolons and colons
- Apostrophes for possession and contraction
- Quotation marks with other punctuation
- Dashes, brackets and ellipses
Parts of speech and agreement
- Subject-verb agreement with tricky subjects
- Pronoun case, reference and antecedent agreement
- Verb tense consistency and the passive voice
- Adjectives, adverbs and comparative forms
- Modifier placement and dangling modifiers
Usage and mechanics
- Commonly confused pairs: their/there, affect/effect, then/than
- Capitalisation and title conventions
- Canadian spelling conventions
- Homophones and spelling patterns
Grammar & Punctuation questions
Is this just a grammar checker?
No. A checker underlines a word and moves on. Here you paste the sentence and get told which clause is the problem and why the rule applies, then you fix it yourself. You can also talk it through out loud, which matters for grammar because most of the confusion is in naming the parts of a sentence, not in spotting that something feels off.
My teacher marks in symbols like CS, frag and agr. What do they mean?
Share the marked page through your camera or screen and the tutor reads the annotations off it. Those codes are close to standard: CS is comma splice, frag is fragment, agr is agreement, mm is misplaced modifier, awk is awkward phrasing. It works through your actual marked sentences rather than generic examples, so you see the pattern you personally repeat.
I speak English fine. Why do I keep losing marks on grammar?
Because written English punishes things speech never does. Speaking has pauses and intonation to separate ideas, and a comma has to do that work on the page. Fluent speakers most often lose marks on comma splices, apostrophes and shifting tense mid-paragraph, none of which you can hear. That is a useful thing, because it means the fix is a small set of rules, not a rebuild.
Can I practise this without writing a whole essay?
Yes. Generate a practice quiz on one rule, like commas after introductory phrases, and it comes back with full worked solutions explaining each item rather than a bare score. Flashcards handle the pairs you keep swapping, and the arcade games can be built from the sentences in your own coursework.
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