The other day a caller to a radio show asked me why he should care about grammar. I told him that if he wanted to communicate clearly he had to follow the same rules as everyone else. Besides, it's a question of social convention. In society, we behave in certain ways to avoid embarrassment. Making a grammatical error is a bit like walking around unaware that your fly's undone. You expose yourself, so to speak.

So, in the interest of clear communication and social ease, let's be aware of grammar and correct usage. Let's discuss some of the grammatical pitfalls we encounter every day. We will begin with pronouns and prepositions.

Pronouns are words like I, he, she, we, and it that take the place of a noun in a sentence, and prevent monotonous repetition. Pronouns have a subjective form or case (I, he, she, we) when the subject of a sentence, and an objective case (me, him, her, us) when the object of a verb or preposition. Prepositions are little words like to, for, by, with, and from, which go before nouns and link them to other parts of the sentence.

A common error is to use I instead of me after a preposition. Recently, my son-in-law asked, "Are you coming to dinner with Jane and I?" "What was that?" said I. "With Jane and me," he corrected himself. You see, the preposition with must be followed by the objective case, me.

A very simple test is to say to yourself, "Are you coming to dinner with I? or are you coming to dinner with me? - which sounds better?" Then put "with Jane and" back into the sentence.

Try it for yourself. Circle the correct form. I have a present for Tom and he/him. Let's give the award to Jane and she/her. The letter is addressed to Mike and I/me.

Some people feel that me is a little impolite or less socially acceptable than I. "Excuse I!" says Dame Edna Everage in keeping with her elevated status. Or, the man of society: "I would be delighted if you would accompany my wife and I to the opera." Or equally incorrectly: "I would be delighted if you would accompany my wife and myself. . ." No, me is always right and proper as the object of a verb (excuse) or preposition (with).

Most of us manage to use the correct pronoun for the subject of a sentence, and avoid such errors as "Me and him will do it" or "Tom and them will go" or "Us kids got into trouble." In all these examples, the subjective forms I, he, they, and we should be used. However, not so long ago a reporter on the CBC news informed us, in talking about a parent, that "him and his wife went to pick up their children". We all have lapses.

As in the earlier examples, the error often occurs when the pronoun is a little distant from the verb or preposition that determines its case. We cannot imagine the CBC reporter saying, "Him went to pick up his children," or the kid saying, "Me will do it." Or my son-in-law: "Come to dinner with I." The ear is often our best guide.

That's all for prepositions and pronouns for now. Don't forget to send in your questions about anything you wanted to know about grammar but were afraid to ask.