of

of ► PREPOSITION 1) expressing the relationship between a part and a whole. 2) belonging to; coming from. 3) expressing the relationship between a scale or measure and a value. 4) made from. 5) expressing the relationship between a direction and a point of reference. 6) expressing the relationship between a general category and something which belongs to such a category. 7) N. Amer. expressing time in relation to the following hour.

USAGE It is incorrect to write the word of instead of have in constructions such as I could have told you (not I could of told you ). This common mistake is made because the pronunciation of have in unstressed contexts is the same as that of of, so the two words are confused when it comes to writing them down.

ORIGIN Old English.