Question

1. I applied cosmetics on my face.
2. I applied the cosmetics on my face.
3. I applied makeup on my face.
4. I applied the make-up on my face.
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Which expressions are correct?

Answer 1

All seem to be correct, except that I don't think the hyphen is needed in #4.

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Answer 2

Thank you. By the way. in which case do we use 'the'?

Answer 3

Most of the time "the" is used to indicate something rather specific. It's idiomatic, though, and not always easy to explain or understand.

Here's a webpage where articles (a, an, the) are discussed:
http://grammar.ccc.commnet.edu/grammar/determiners/determiners.htm

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