Sometimes lf lam dowloading a torrent l may get 80% of it and then stops.
Is there any way that l could play the downloaded part instead of waiting for the total torrent to finish?
Its frustating that you have most of it but can't listen to it.
Any help will be appreciated.

You can play it if you disconnect from your torrent totally (not just 'pause') BUT what you will hear is a bit weird. Remember that you're not d/l'ing in a linear fashion from start to finish, but rather you're getting 'packets', you'll get a bit from one song, then another bit from another etc. It doesn't come together till it's all finished. If you try & play an unfinished track, it will play ok for a while but then you'll get a bit from a different track, then maybe back to the first one, it will be all over the place, it sounds as if it's corrupted but it ain't. So, yes, you've got 80%, but not from start to finish.

The question then, is why you can't d/l any more. Is there a 'seed' ie, someone with the whole file, if there is then you should be able to get the whole thing. If not, have a look at how many 'peers' there are, ie, guys like you with only part of the file. If you see something like 'seeing 0.8 of copies' or some such, then you know that only 80% is distributed amongst all of you, after a while all of you will be stuck on 80%, you'll all have shared what everyone else has, the bane of torrenting! You'll have to wait until a 'seed' logs on & you can complete the file then.

Sometimes there won't be a seed but you'll see 'seeing 1.5 copies' in which case you're alright as there is more than a full copy but it's spread out amongst all of you.

Winamp will play those partially finished files but you won't be able to convert then to anything else.

Thank You very much,vox12string.
l will keep trying to see if finally l get the complete download.

The person or persons who were "seeding" that Torrent probably went "off-line". Typically you'll just have to wait (sometimes for days!) until a "seeder" comes back on-line.