To have

Hi,
I'd like to know how have and its forms are pronounced (in American English), I'm not sure when it's pronounced with a schwa. I'll use the phonetic transcription used by the Merriam-Webster dictionary:
a like in cat
& is the schwa, like the a in about
s like in snake
z like in zebra

Ok, I have no problems (I hope so) when the forms are contracted. I'd like to understand how the forms are pronounced when they are not contracted (/hav/ or /h&v/?). I think it's also important to show which words are stressed in the sentences.

   1. I have seen your girlfriend.
   2. I haven't seen your girlfriend.
   3. I had seen your girlfriend.
   4. I hadn't seen your girlfriend.
   5. I have a black car.
   6. I have to buy a new laptop. (This shoud be /haft&/)
   7. I don't have to buy a new laptop.
   8. He has to buy a new laptop. (/haz t&/ or /has t&/? And is the t a tapped t, like in "way to go"?)

(Ex. of possible answer: #1 - stress on "seen" - have is /h&v/)

Thank you very much in advance

1. I have seen your girlfriend. /hav/
2. I haven't seen your girlfriend. /havint/  /i/ nearly absent.
3. I had seen your girlfriend. /had/
4. I hadn't seen your girlfriend. /hadint/  /i/ nearly absent.
5. I have a black car.  /hav/
6. I have to buy a new laptop. (This shoud be /haft&/)  yes.
7. I don't have to buy a new laptop.  /haft&/ again
8. He has to buy a new laptop. (/haz t&/ or /has t&/? And is the t a tapped t?  /hast&/; no, not tapped.

Not contracting auxiliary have is relatively rare in conversation.

CJ

So when are they pronounced that way?

Never when I say them!

I think contracted forms can be pronounced either with a schwa or without (/&v/ or /v/, /&z/ or /z/, /&d/ or /d/).

Yes, as you've shown. 

But they have no h's, so I wonder when I could hear them with the h's.

I wonder the same thing!

CJ

Good idea.

( ... won't use them either then  )

CJ