最新整理（四）！高考英语24语法，带你攻克高中所有语法难点！(28)

⑵ 三种形式都有变化

㈢ 现在完成时标志词
recently；recent years；these days/years；lately；since；for 段时间；in the past few years；ever since；in the last five months；up to now；since then；so far；ever；never,yet；once；twice；already；before；just
⒈ already（已经）：用于肯定句
如：I have already posted the letter.
⒉ yet(已经）：用于否定句，疑问句
如：He hasn"t done his homework yet.
⒊ just（刚刚）
如：They have just left.
⒋ ever(曾经）
如：Have you ever been to Beijing?
⒌ never(从不）
如：I have never seen him.
⒍ before（以前）
如：Have you seen the film before?
⒎ since（自从.…以来）
如：I"ve worked in the school since 1999.
⒏ for(长达）
如：He"s lived in Shenzhen for 6 years.
⒐ in the past several days/weeks/ years（过去的.…)
⒑ recently（最近）
如：I have not written to my parents recently.