How long have you worked here?
Please correct my Chinese grammar.

你在哪儿工作？Where do you work?
我在这里工作。I work here.
你在这里工作了多长时间吗？How long have you worked here?
我在这里工作了九年。I have worked here nine years.

Thanks :-)

Question

How long have you worked here?
Please correct my Chinese grammar.

你在哪儿工作？Where do you work?
我在这里工作。I work here.
你在这里工作了多长时间吗？How long have you worked here?
我在这里工作了九年。I have worked here nine years.

Thanks :-)

Answer

你在哪儿工作？Where do you work? ( can cancel 儿 because 儿 is how people from northern china pronounce, it is ok if it is not canceled）
我在这里工作。I work here.
你在这里工作了多长时间吗？How long have you worked here? （cancel 吗）
我在这里工作了九年。I have worked here nine years.

well done

Answer

the first, second and forth sentences are correct.
the third sentence should cut out "吗"