You use of to combine two nouns when the first noun identifies the feature of the second noun that you want to talk about.
You use of to combine two nouns, or a noun and a present participle, when the second noun or present participle defines or gives more information about the first noun.
You use of after nouns referring to actions to specify the person or thing that is affected by the action or that performs the action. For example, 'the kidnapping of the child' refers to an action affecting a child; 'the arrival of the next train' refers to an action performed by a train.
You use of after words and phrases referring to quantities or groups of things to indicate the substance or thing that is being measured.
You use of after the name of someone or something to introduce the institution or place they belong to or are connected with.
You use of after a noun referring to a container to form an expression referring to the container and its contents.
You use of after a count noun and before an uncount noun when you want to talk about an inpidual piece or item.
You use of to indicate the materials or things that form something.
You use of after a noun which specifies a particular part of something, to introduce the thing that it is a part of.
You use of after some verbs to indicate someone or something else involved in the action.
You use of after some adjectives to indicate the thing that a feeling or quality relates to.
You use of before a word referring to the person who performed an action when saying what you think about the action.
You use of after a noun which describes someone or something, to introduce the person or thing you are talking about.
If something is more of or less of a particular thing, it is that thing to a greater or smaller degree.
You use of to indicate a characteristic or quality that someone or something has.
You use of after the verb 'be' to indicate a characteristic or quality that someone or something has.
You use of to specify an amount, value, or age.
You use of after a noun such as 'month' or 'year' to indicate the length of time that some state or activity continues.
You can use of to say what time it is by indicating how many minutes there are before the hour mentioned.