Omission of the particle は > In the sentence above there is no after . Can we say `` If we can, does the omission of mean lack of formality? I have come across another sentence similar to the one above: > ****

In that case, there are two cases. One is omission of the particle , the other is just a call. You can judge it by the context. would be the former case, but is the latter case.

The omission of in the former case is colloquial.