since + past simple/present perfect

[mafto]

Here ( Learning English | BBC World Service ) they say that "It's been a long time since I had pasta." and "it's been a long time since I have had pasta." are both correct.

What about the first verb, then? Could someone also (correctly) say "Since the time I have been a teenager I have changed my mind?"
And what about "Since the time I have been a teenager, I changed my mind" ?

Thank you very much :)

[nouamaneer]

Interesting!

[5jj]

Here ( Learning English | BBC World Service ) they say that "It's been a long time since I had pasta." and "it's been a long time since I have had pasta." are both correct.

The second is another way of saying. "I haven't had pasta for a long time", and is fine. We can't say, "Since the time I have had pasta it has been long".

Could someone also

say "Since the time I have been a teenager I have changed my mind?"?
And what about "Since the time I have been a teenager, I changed my mind" ?

No and No. If you are still a teenager you could say, "I have changed my mind since I became a teenager" or "I have changed my mind since I have been a teenager".

[JarekSteliga]

[COLOR=#333333][FONT=Verdana] ... "I have changed my mind since I have been a teenager".

NOT A TEACHER

I have to say that I find this disconcerting. I remember a rule accoring to which Present Perfect "works" since a given point in time untill now. "Having been" a teenager hardly seems a point in time to me, but rather an extended period of time. Somehow "having become" a teenager works better for me, as it suggests a point in time.

I also have to admit that "Present Perfect" since "Present Perfect" structure is a revelation to me. "Present Perfect" since "Simple Past" has always seemed only correct. I suppose on your and the BBC's authority I am bound to try (not an easy thing to do at my age ) to also work the former into my English grammar.