常用的连词有哪些？那些 是用于 句中？ 那些用于句首？ however 属于什么词？

英语中的连词主要分为两类：并列连词和从属连词。并列连词用来连接平行的词、词组或从句,从属连词常用来引导从句。
一、并列连词 ：
1.表示语义引申 ：
and，neither... nor， both... and ，not only... but also ， as well as
2.表示选择：
or ，either... or
3.表示转折或对比：
but / yet / however / nevertheless
4.表示因果关系:
for / so / therefore / hence
二、从属连词
1.引导时间状语从句：
when / while / as / after / before / since / until(till) / as soon as
/once
2.引导原因状语从句:
because / as / since / now that / considering (that) / seeing that
3. 引导条件状语从句:
if / even if / unless / in case / provided ,providing (that) / suppose ,supposing (that) / as (so) long as / on condition (that)
4.引导让步状语从句:
although / though / even if (though)
5.引导比较状语从句:
than / as (so)...as
6.引导目的状语从句:
lest / so that / in order that
7.引导结果状语从句:
so...that / such...that

纯手打 希望采纳 有不会的在线问都可以

and,but,both...and,as well as等，but,when,where,why等具体要看情况，没有绝对的。however是连词，