1.虽然(表示对比)
You usealthough to introduce a subordinate clause which contains a statement which contrasts with the statement in the main clause.
e.g. although he is known to only a few, his reputation among them is very great...
虽然知道他的人不多,但他在这些人中名声却很响。
e.g. although the shooting has stopped for now, the destruction left behind is enormous.
虽然枪战目前已停止,但造成的破坏是巨大的。
2.虽然(表示惊奇或出乎意料)
You usealthough to introduce a subordinate clause which contains a statement which makes the main clause of the sentence seem surprising or unexpected.
e.g. although I was only six, I can remember seeing it on TV...
虽然那时我只有6岁,我依然记得在电视上见过它。
e.g. although he was twice as old as us, he became the life and soul of the company.
虽然他的年纪是我们的两倍,但他却成为了公司的灵魂人物。
3.尽管,即使(表示让步)
You usealthough to introduce a subordinate clause which gives some information that is relevant to the main clause but modifies the strength of that statement.
e.g. He was in love with her,although he did not put that name to it.
他爱着她,虽然他没有将其称为爱。
4.尽管;虽然(表示承认所述是事实)
You usealthough when admitting a fact about something which you regard as less important than a contrasting fact.
although的解释
e.g. although they're expensive, they last forever and never go out of style...
尽管价格昂贵,但它们经久耐用,永不过时。
e.g. although not ideal, this attitude is not entirely destructive.
这种态度虽然不够理想,但还不至于消极透顶。