GUIDE深度 · Deep dive
Articles, Prepositions and Passive Voice
Articles depend on sounds, not letters: an hour, a university. Prepositions are collocations: interested in, good at, depend on. Passive is be + past participle, with tense and agreement.
Articles
an before vowel sounds: an apple, an hour.
a before consonant sounds: a university, a useful book.
the for specific or unique things.
Passive
was/were + past participle.
by introduces the doer and can be omitted.
FAQ
Why an hour?
The h is silent, so it starts with a vowel sound.
How to question a passive?
Move was/were forward: Was the letter written?