👉🏻We use all of before personal pronouns (us, them), demonstrative pronouns (this, that, these, those) and relative pronouns (whom, which). The personal pronoun is in the object form:
🔹I need to speak to all of you for a few minutes.
🔹He brought gifts for all of us.
🔹We had to contact the insurance firm and the airline, all of which took a lot of time. (all of which = ‘contacting the insurance firm and the airline’)
👉🏻With demonstratives (this, that, these, those) we can say all of or all without of:
🔹All (of) this has to go out into the rubbish bin.
👉🏻We often use of after all in definite noun phrases (i.e. before the, possessives and demonstratives), but it is not obligatory:
🔹All (of) the workers were given a pay-rise at the end of the year.
🔹I gave all (of) my old books to my sister when she went to university.
🔹What shall we do with all (of) this cardboard? Throw it out?
👉🏻We use all, not all of, before indefinite plural nouns referring to a whole class of people or things:
🔹All cats love milk.
Not: All of cats love milk.
🔹This book was written for all children, everywhere.
👉🏻We use all, not all of, before uncountable nouns:
🔹All junk food is bad for you.
Not: All of junk food is bad for you.
🔹I love all music, not just classical.
👉🏻When we use most before articles (a/an, the), demonstratives (this, that), possessives (my, your) or pronouns (him, them), we need of:
🔹Most of the information was useful. Some of it wasn’t relevant.
Not: Most the information …
🔹They sold most of their apartments quite quickly.
👉🏻When there is no article, demonstrative or possessive pronoun, we don’t usually use of:
🔹there hasn’t been much rain. Most rivers are below their normal levels.
Not: Most of rivers are below their normal levels.
👉🏻We use most of before geographical names:
🔹Most of England and Wales should be dry throughout the day.
👉🏻We use some with of before the, demonstratives (this, that), pronouns (you, us) or possessives (my, your). We use some of to refer to a part of a whole:
🔹I wasn’t sure about some of the answers.
🔹 It was great to meet some of her friends and colleagues.
Not: … some her friends …
🔹First a look at some of today’s main stories in some more detail.
👉🏻We can use half and half of before nouns with the definite article (the), possessives (my, your) and demonstratives (this, that):
🔹We spent half the time talking. It was an absolute waste of time for all of us.
🔹Why don’t you have half my chocolate?
🔹At least half of those books can be sold.
👉🏻Half of, not half, can occur with a pronoun as head of the noun phrase:
🔹Almost half of us were not allowed to vote. It was completely unfair.
👉🏻Half, not half of, is used in the pattern half a/an and is followed by a noun of measurement:
🔹It’s at least half a kilometre to those shops.
Not: … half of a kilometre … or … half kilometre …
🔹It’ll take me half an hour so I’ll see you at the club.
Not: … half of an hour … or … half hour …