Is the following sentence grammatically correct? “It’s been 11 months since you stopped visiting us.”

Answer

Dear John,

You’re right. The sentence

It has been 11 months since you stopped visiting us.

contains a so-called contamination. A contamination is: “mixing up or confusing meaning-related words or expressions, resulting in a wrong new word or expression” (= definition of Van Dale). So you can confuse more and more and more with each other, causing you to say more and more by mistake.

In your sentence, the confusion is a bit more complex, but the confusion becomes visible when you put the two possible correct sentences together:

It has been 11 months since you visited us.
You haven’t visited us in 11 months.

Those two possible correct sentences have become confused. There are two solutions to untangle the confusion. One of those possibilities is – as you suggest – not to omit the words anymore. But you can also choose the other option, which is not to leave it standing and it is … omitted. But then you have to rearrange the words in that sentence a bit.

Yours faithfully,

Peter Debrabandere