I agree with James. Your sentence is grammatically sound, but not very meaningful. The adverb 'basically' should not be modifying 'able'. It is the word 'English' which should be modified. You can say "He is able to communicate in basic English" or something like "He is able to communicate in a basic way in English."

I think, there is no grammar mistake in your sentence. sound good

I think that you're trying to say: 'He is able to communicate in basic English' i.e. he can speak a little english; enough to get by...

You could say, "He is more or less able to communicate in English.". This has a different feel from the first correction. It's an informal way to suggest that he speaks well enough to get the idea across but with mistakes.

Ok