however
adv.无论如何；不管怎样 （语义上=anyway,at all events）引导状语从句.
conj.然而；可是（语义上=whereas,while,nevertheless,but,yet）,用于引导【并列句或链接并列成分】,可以位于【居首,句中或句末】.
例如：
Your answer,however,is wrong.
However,your answer is wrong.
Your answer is wrong,however.【转折连词】
We should try all out to finish the task in time however hard it is.【连接副词】
【However连接副词,引导状语从句】 cold it is,she always goes swimming.