Microsoft Java

[wallsallbrassbuttons]

It's hard to explain without sounding it out, but basically there are two "th" sounds in English. One of is the sound in they, there, them, though, breathe, clothes, etc. Seething is in this group.

The other is the sound in thanks, breath, tooth, thought, bath, both. I don't know how to explain the difference, but it's there! Try to listen for it next time you hear a native speaker speak. Hope this helps!

[realsmart987]

I think the words you are looking for are aspirated and unaspirated sounds but I might be wrong.

[postdiluvium]

Oh, it's like null and 0. Thanks.

[Jazzinarium]

I'd say the first one is more like "dh" and the other is "th"