(2)你哥哥参军多长时间了？
错误：How long has your brother joined the army?
正确：
延续性动词与非延续性动词之间的转换
leave --- be away borrow --- keep buy --- have begin/start --- be on
die --- be dead finish --- be over fall ill --- be ill
get up---be up catch a cold --- have a cold come here --- be here
go there --- be there become --- be come back --- be back
fall asleep --- be asleep get to/ arrive/reach --- be (in) leave --- be away from
get to know --- know go (get) out →be out put on→wear
join----be a member of ... (成为…的一员) open ---be open close ---be closed
The old man died 4 years ago.----
He joined the Party 2 years ago.----
I bought the book 5 days ago.----
五、现在完成时态与一般过去时态的区别
1 一般过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。
I saw the film yesterday.
I have seen the film
2 一般过去时和表示过去的时间状语连用，如：…ago, last week/. In 2008, in the past, just now, the day before yesterday, yesterday ....... Then(那时),that day, one day, once(从前)
现在完成时常和r ecently（近来），ever, never, twice, so far（到目前为止）, since，for，in the past/last few years , already（肯定句）, yet（否定，疑问句）, just(刚刚), before（以前）连用。
六、比较have/has been to、have/has gone to 和have been in
have(has) been to. 表示“曾去过某地，已经从那里回来了”，可以和ever、never、twice 等连用。
have(has) gone to 表示“已经去了某地，在去那里的途中或到达那里还没有回来”。
have(has) been in 表示“在某地呆多长时间”，常与表示一段时间的状语连用，如：since, for, how