Scientific English as a Foreign Language
Answers to Lesson of January 9, 1998
Its&It's, Whose&Who's

The two most common mistakes (even by native speakers) concerning the use of the apostrope are to confuse "its" with "it's"; and "whose" with "who's". These are two examples of using the apostrophe for a contraction- it represents missing letter(s). "It's" means "it is" and "who's" means "who is". In contrast, both "its" and "whose" are posessive pronouns.

1. The computer doesn't work. Its disk drive is broken.

2. The weather is nice today. It's beautiful.

3. I see a book on the table. Whose is it?

4. That student, who's very lazy, will never graduate.

5. The researcher, whose schedule was very unusual, was at work every night until midnight.

6. Apple Computer is in trouble. Its future is in doubt.

7. Who's responsible for this equipment?

8. We shouldn't use this equation because it's not valid for this temperature range.

A professor of Physics named May
Complains of the classroom today,
"The problem, you know,
Is that they're too slow.
We were far better students than they."

His friend, a professor named Beecham,
Said "It's true, you don't seem to reach 'em.
But they're not to blame,
For they haven't the same
Class of teachers that we had, to teach 'em!"

-B. Elliott

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Created April 30, 1998, by Nancy Burnham and Fred Hutson.