Green Belt
Perfect aspect, the passive, relative clauses, and the finer shades of modality.
Result/completion vs. duration/ongoing activity.
Marking the earlier of two past events.
Unreal/hypothetical past and regret.
Past condition → present result, and the reverse.
Form across tenses and when the passive is preferred.
Word order in reported questions; ask/tell + infinitive.
Commas, that restrictions, essential vs. extra information.
Expressing certainty and probability about now.
Modal + have + past participle to deduce about the past.
The verb after wish shifts with meaning: past for the present, past perfect for the past, would for annoyance.
Arranging for someone else to do something for you.
In progress at a future time vs. completed by a future time.
The same verb means two different things depending on -ing or to.
Generic reference and systematic zero-article patterns.
Although needs a full clause, but despite and in spite of need a noun or -ing form.
Each linker has its own grammar and punctuation, even when the meaning is similar.
Auxiliary agreement and positive/negative polarity.
Combining intensifiers with that-clauses and infinitives.
The + comparative ... the + comparative; far/much + comparative.
Object and pronoun placement; separable vs. inseparable verbs.