no mistake or nomistakes?
Tom made no "mistakes" in his test.
Tom made no "mistake" in his test.
Can I say this sentence in both of the two ways?

Question

Answer

At least in American English, “mistakes” is the much more common way to say this, but it is OK with “mistake.”

Answer

The first one is much more common, I think. I would use "on" instead of "in". You could also say "Tom didn't make any mistakes on his test." If someone says "on his test", I think that the test is written. If someone says "in his test", I think that the test may be written or that it could possibly by a speaking test or another type of test.