Pronunciation doubt

[Thania]

Hi!
I was wondering if somebody could help me. Is there any rule to know when the TH has ð or θ sound? I would really appreciate if somebody helped me.

[j4mes_bond25]

Hi!
I was wondering if somebody could help me. Is there any rule to know when the TH has ð or θ sound? I would really appreciate if somebody helped me.

Interesting question, mainly because, I'm yet to enlighten myself with the same query.

In some cases, the "th" is NOT just have "ð or θ" sound, but could have just "t" sound, as in the case of:

>> "Thomas" = tom.as (with "t" sound)
>> "Thames" = teI.ms (with "t" sound, again)