NOTE: (1) More colloquial forms of keredomo are keredo, kedo, and kedomo. Keredomo in all its forms are used to lend a softer tone, and in its full form (not the alternative forms) tend to be preceded by desu and the -masu verb forms. (2) In each of the usages below, ga (#2, II-1, 2, 4, 5, 6) can replace keredomo and its more informal variations.
1. Used between two clauses when indicating that they are opposed in meaning: "but, although."
Tenkeyohō de kyō wa ame wa furanai to itta-n desu keredomo, yūgata kara futte kimashita ne.
They said on the weather report that it wouldn't rain today, but it began raining in the evening didn't it.
Takeuchi-san ni denwa o kaketa keredo rusu deshita.
I called Takeuchi, but she was out.
2. Used at the end of a sentence, implying something that qualifies what is actually stated: "well, yes, but..."
NOTE: This usage is essentially the same as that in ex. 1, above, except that here the second clause isn't stated outright. (Words in brackets below show only one of various imaginable contexts.)
Tamani wa ryokō ni mo ikitai to omotte iru-n desu kedo…
I'd really like to go on a trip once in a while ... [but I don't have the time].
Watashi wa gorufu o shinai wake de wa nai-n desu kedo...
It's not that I don't play golf ... [but I really don't like it that much].
3. Indicates a preliminary remark.
Mada hassha made ichi-jikan mo arimasen kedo, dō shimashō ka.
There's still an hour until [the train] departs, [so] what shall we do [in the meantime]?
Tani desu kedo, Tomoko-san irasshaimasu ka.
This [my name is] is Tani. Is Tomoko there?
Hope this helps!
°˖ ✧◝(○ ヮ ○)◜✧˖ ° こゆうきあいはら °˖ ✧◝(○ ヮ ○)◜✧˖ °