Back when I was writing about ablaut reduplication, I read this article on the BBC website, which mentions this unwritten rule, and other structures that we use unconsciously. It’s interesting and worth reading, but I was struck by one passage in particular:

There are so many tenses you can use without even thinking about it, and almost certainly without being able to name them. It depends how you count them, but there are about 20 that you deploy faultlessly. The pluperfect progressive passive for an extended state of action that happened to you prior to another action in the past is, when you put it like that, rather daunting. But then you’d happily say “I realised I’d been being watched” without breaking sweat or blinking.

Eh, not quite without breaking a sweat, I think! Certainly the sentence is grammatically correct, and an example of the passive voice. The active version would be I realised someone had been watching me. We then change that to passive by changing the verb to the past-participle form (watched) and using the appropriate form of to be (had been being – past perfect continuous). But is it really that easy for even a native speaker to say this, and how often would we really use this form?

The obvious problem with this sentence is that it sounds strange, with been and being, which sound almost identical in spoken English, right next to each other. We usually try to avoid having (almost) identical words adjacent to each other, even if it’s grammatically correct, because it sounds odd. That’s why we prefer to say I didn’t eat lunch because I’d had a late breakfast, instead of I didn’t eat lunch because I had had a late breakfast. Because we there we tend to automatically avoid using the present perfect continuous passive (I realise I’ve been being watched) or the past perfect continuous passive (I realised I’d been being watched).

And this is easy enough to do because we can always avoid using the passive, without any real negative effect. While we often try to avoid using words and phrases like someone or some people because they can sound weak, is there anything wrong with I realised someone had been watching me (the active voice)? Someone doesn’t sound weak here because we don’t know who had been watching us, and we’re not expected to know.  And we don’t even need to use the continuous form in this case: I realised I’d been watched works pretty well too (though with a suggestion that there was a gap between the end of the watching and the moment of realisation). Both of these sentences are better, in my opinion, because they’re shorter and clearer, and don’t really affect our meaning.

It feels a little strange to recommend not using perfectly legitimate grammatically-correct structure in English. But as I always say, you have to consider both strict grammatical accuracy and practical communication. Usually the two concepts go hand in hand, and that’s basically what grammar is: a system to allow smooth communication. But occasionally strictly following grammar rules impedes communication. This is because English is a rich language with many structures, and rules therefore won’t work as well with every structure. The passive voice works well with the present simple, present continuous, present perfect simple, past simple, past continuous, past perfect simple, will (kind of), and going to, but not with the present perfect continuous or the past perfect continuous (mainly just because been being sounds strange). Should we then change the passive somehow because it doesn’t quite work perfectly with every tense? Considering how seldom we ever need to use the present or past perfect continuous passive, the passive voice as it is, is good enough (yes there are two is‘s together there, but it sounds ok, doesn’t it? It’s because of the pause between them).

Grammar purists might balk at the idea that good enough is acceptable, but that’s how our grammar developed. People naturally used the forms that made communication easy, even if that meant not using the passive voice when it was technically possible to do so. So don’t worry if you do break a sweat trying to say I realised I’d been being watched: that just makes you normal!