现在完成时的几个问题1、He has come back home just now.2、I'm glad you've

he came back home just now.
just now 是表示刚才.不是时间段.不能用完成时.所以用一般过去时.
How long have you been there.
stay是短暂性动词.不能和how long问的时间段连用.所以用been.延续性动词
He has been in India for a week.
for a week一个星期.是时间段.不能和go短暂性动词用.所以用been.
He has gone to Beijing since two years ago.
since two years ago表示的是两年前.two years ago是一个时间点.所以不用been.用gone..
总结.
时间点用短暂性动词.时间段用延续性动词.

1. He came back just now just now只能与过去时联用，
2. How long have you been there? how long与长时间联用，stay是短动词
3. He has been to India for a week go是短动词，不能与长时间for a week连用
4. He has been in Beijing s...