American English usage: in (a) achool

[Sitifan]

1. He is an English teacher in a junior high school.

2. He teaches English in a junior high school.

3. He is an English teacher in junior high school.

4. He teaches English in junior high school.

#1 and #2 are correct. Are #3 and #4 also acceptable in American English?
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Thank you very much for your reply.

[Kitosdad]

Good morning Sitifan,

All of your examples serve their purpose.

They state clearly his occupation, and the place of his employment.
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Keep it simple ... Keep it interesting.

[Jamie (K)]

All of the sentences are acceptable in American English, with the article and without.

When the article is used I picture a building in my mind, where he teaches.
When the article is not used I imagine the level or curriculum he teaches.