A controversy blew up in New South Wales yesterday when Luke Foley, the Labor opposition leader, told a radio station that his single mother had '... invested her whole life into us, my sister and me, and I owe her everything...'.

Apparently the talkback radio lines went into overload as caller after caller complained that Foley should have said 'my sister and I' not 'my sister and me'.

In fact Foley was correct. If we take a trip back to your primary school English classes you should remember that thing about sentences having a subject and an object. In the sentence 'Bob hits Bill', Bob does the hitting so is the subject; Bill is being hit so is the object. With personal pronouns, the subject form 'I' should be used when you are, well, the subject. The object form 'me' should be used ... you get the idea.

In Foley's sentence, he and his sister were the the objects of the sentence (they were the ones being invested into by their mother, who was the subject). Hence 'my sister and me' was right.

There's an easy test for this. Simply take the extra person out of the sentence and see how it reads. If Foley had been an only-child he would have said, 'My mother invested her whole life into me'. No one would have expected him to say 'My mother invested her whole life into I'. Adding a sister doesn't change this.

(There are many more complete explanations of this on the web, including here.)

Linguists call the whole 'and I' thing an example of 'hypercorrection': the phenomenon of over-applying a grammatical rule because it was drilled into us as youngsters and/or because we want to sound more refined. Overusing 'whom' is another example, as is refusing to start a sentence with 'and' or 'but'.

The lesson? Just because your mum/dad/teacher/priest pointed out your failings as a youngster doesn't mean they were right. You've probably realised that now about more than a few aspects of life. Now you can add grammar to the list.

As usual, if you have any questions or comments, please add a comment below or contact me.