during over since for的用法和时态

during
表示在.期间,没有时态限制,可能是现在,可能是过去.
throughout the course or duration of (a period of time) :the e.g.restaurant is open during the day.
the period during which he grew to adulthood.
over
这个意思就多了,甚麼超过啊,路过啊.
be over 表示不在受甚麼东西影响了.e.g.we were over the least.
over and over就表示一遍一遍的
反正over就有超过,覆盖的意思,更加没有时态限制.
since
意思：“自从...起”.一般用现在完成时态
表示“因为”意思时候,没有时态限制
long since做副词时候也不需要用完成时态.
preposition,conjunction,& adverb
1 in the intervening period between (the time mentioned) and the time under consideration,typically the present :[as prep.] she has suffered from cystic fibrosis since 1984 | the worst property slump since the war | [as conj.] I've felt better since I've been here | [as adv.] she ran away on Friday and we haven't seen her since.
2 [ conj.] for the reason that:because :delegates were delighted,since better protection of rhino reserves will help protect other rare species.
3 [ adv.] ago :the settlement had vanished long since.
for
指一段时间的长度.
我已经13年没有见她了.
I have not seen her for 13 years
I have not seen her since 1995.
indicating the length of (a period of time) :he was in * for 12 years