You use although to introduce a subordinate clause which gives some information that is relevant to the main clause but modifies the strength of that statement. He was in love with her, although he did not put that name to it. = though
You use although to introduce a subordinate clause which contains a statement which makes the main clause of the sentence seem surprising or unexpected. Although I was only six, I can remember seeing it on TV = though
You use although when admitting a fact about something which you regard as less important than a contrasting fact. Although they're expensive, they last forever and never go out of style
You use although to introduce a subordinate clause which contains a statement which contrasts with the statement in the main clause. Although he is known to only a few, his reputation among them is very great Although the shooting has stopped for now, the destruction left behind is enormous