1.all as an adjective means "all", "all", "whole" and "all" and can be used as an attribute or predicate in a sentence. For example:

Let's call it a day. Let's call it a day. (as a predicative)

All my books are in the box. All my books are in this box. (as an attribute)

Note: when all is used as an attribute, it should be placed before the definite article the, demonstrative pronouns this, that, these, those or adjective subject pronouns. For example:

All his friends will come tonight.

All his friends are coming tonight.

All his friends are coming tonight.

2.all is used as an adverb, meaning "all", "all" and "complete". It is mainly used to modify adjectives, adverbs or prepositional phrases and as adverbials in sentences. For example:

We were all wrong. We were completely wrong.

3.all is used as a pronoun, meaning "all", "all", "everyone" and "all", which can refer to both singular nouns and plural nouns. It can be used as subject, object and appositive in sentences. For example:

Everything is ready. Everything is ready. (as subject)

Everyone is ready to play football. Everyone is ready to play football. (as subject)

I know all of them. I know all about it. (as an object)

They are all working hard. They are all working hard. (appositive)

Note: When all is used as appositive, it should be placed after be verb and auxiliary verb and before action verb. For example:

We are all students. We are all students.

We all want to help her. We all want to help her.

Two. All and all the differences.

1. Only all of can be used before the personal pronoun accusative, not all. All of those men are friends of mine. All of those men are friends of mine.

2. When there is no determiner before a noun (such as definite article the, adjective subject pronoun, demonstrative pronoun, possessive case of a noun, etc.). ), you can only use all, not all. All the children like watching TV. All the children like watching TV.

When a noun is modified by a determiner, you can use both all and all. All the children like watching TV. All these children like watching TV.