Non native speaker?

[Matthew Gordon]

This treatment of the interdental fricatives is one of the commonly reported
features of AAVE (African American Vernacular English) phonology. The
appearance of stops in initial position for Standard English fricatives is
found in vernaculars all over the US and Britain (and maybe elsewhere). The
pattern of [f] for [theta] is, I think, more restricted but not exclusive to
AAVE. I don't have Wells here to check.

Duane Campbell wrote:

>
> While I'm asking questions, Chief Moose (who is, incidentally, Dr. Moose)
> replaces all of his "th" sounds with either a hard "D" (initial) or "F".
> I have heard this from time to time, though usually not so pronounced,
> including a classmate in 1950s rural Pennsylvania with a 100 percent
> white school population. I had always assumed it was a minor speech
> impediment (is there a new PC word for this?) or an ideomorph. Are there
> dialects that include this shift?
>
> D