现在完成时

现在完成时的构成

• has + 过去分词
• have + 过去分词
eg：I have'n't seen you for a long time.

现在完成时的用法

• 表示迄今为止完成的事情
  eg：He has already come.
• 表示过去的事情对现在的影响
  eg：I have broken up with my boyfriend.
• 强调‘已经’完成的事情
  eg：I have already been to Hangzhou.
eg：Have you been to Hangzhou yet?
• since与for
since + 时间点
  eg：I have been in Shanghai sice 2015.
for + 时间段
  eg：I have been in Shanghai for 4 years.
• 主语 + be 动词 + the most + 形容词 + 名称 + 现在完成时 表示迄今为止最...的
  eg：It is the most amazing moive I've ever seen!
eg：Canon is the most beautiful music I have ever heard.