You don't normally use Present Perfect with stative verbs (have, be, like, seem, prefer, understand, doubt, know, etc.) Here's a longer list - in general, they apply to states that last for some time.
In some contexts, such as "How long have you had/been having these symptoms?", there's no real difference. Arguably, been having calls more attention to the fact that you're still having the symptoms, but I doubt many people would consciously either make or hear that distinction.
A "rule of thumb" for to have is: when it means to experience, you might want to use Present Perfect; when it means to own, you almost certainly don't.
Here's an example for to be using the "slightly unusual" Present Perfect in a construction which is perfectly valid, and is probably the most succinct way of expressing the intended meaning...
By now the new cook will have been being introduced to her duties for several weeks.
The relevant grammatical rules involved here are
- The Perfect auxiliary have must be followed by the past participle form of the next verb.
- Modal auxiliary verbs like will must be followed by the infinitive form of the next verb.
- Conjunction Reduction optionally deletes the first of two identical verbs following auxiliaries.
The question is what counts as "identical" for conjunction reduction.
And the answer is that "identical" means "identical in sound". Nobody would ever say this sentence, for precisely the reasons described in the answers and comments here. That is, this isn't a question about English; this is about English spelling and reading, which is technology, not linguistics.
The problem with this sentence is that it looks like it's OK, but it doesn't sound like it.
Take a verb like sing, sang, sung, with different infinitive (sing) and past participle (sung) forms.
Then both
- *He has or will sing that song
- *He has or will sung that song
are ungrammatical, no matter which form is used.
And that's why
- *He has or will read that book
is ungrammatical. It could only happen in writing; it's a cheat, like a sight rhyme. It really should be
- He has red or will reed that book
(spelled funnetikly)
because words pronounced differently can't do conjunction reduction.
And spelling doesn't count.
- No English grammar rule has anything to do with spelling or punctuation.
If you try verbs with identical infinitive and past participle forms, like the set of
monosyllabic final-t verbs like set, set, set; cut, cut, cut; or put, put, put:
- He has or will set the plan in motion.
- He has or will cut them some slack.
- He has or will put it on display in the main gallery.
These sound perfectly grammatical (if needlessly complex), to me. This despite the facts that
- the set, cut, or put following will must be an infinitive,
but
- the set, cut, or put following has must be a past participle.
The abstract grammatical category of the deleted verb seems to be irrelevant -- as long as they sound the same, they're identical. And as long as that's the case, you can delete the first one.
Best Answer
It's not really good English grammar. It does feel awkward, as has been noted. That's the giveaway, to a native speaker.
And of course nothing like this is treated in school grammars, because they're still talking about English as if it were Latin, with six tenses, two voices, three or four cases, and all sorts of other zombie phenomena. This educational deficiency afflicts both native speakers in Anglophone education, and foreign learners in ESL classes worldwide.
The reason it's ungrammatical is that it runs afoul of what Haj Ross called the Doubl-ing Constraint in his paper on the subject. (Unfortunately, ERIC doesn't have the full text of the paper available, for some bureaucratic reasons, but the link shows the abstract.)
The gist of this constraint is that under certain circumstances (which the paper spells out in detail), one can't use two present participles (-ing forms of a verb) together, with one governing the other.
I.e, the following are just out:
Even though comparable sentences without double -ing are fine:
There is a lot of speculation about how and why this rule operates, but mostly it seems it just interferes with the parsing routines of many native speakers; i.e, it's a purely syntactic rule, totally unconscious and automatic, concerned solely with form, not meaning.