since的用法：譯作“自從…以來”
(1)接時間點：如 I have stayed in that country since 1995.
要求：謂v.用現在完成時,而且須是延續性動詞.
(2)接一段時間 + ago：如 They have lived in that house since two years ago.
(3)接時間狀語從句：如 I have loved her since I met her last time./ Lily has stayed at home since she left school.
要求：主句的謂v.用現在完成時,而且須是延續性動詞；從句的謂v.用一般過去時,而且須是終止性動詞.
(4)用於句型“It’s / It has been + 一段時間 + since + 時間狀語從句”中,譯作“自從…以來,已經…(時間)了”.如 It’s / has been three months since he moved to this city.
要求：主句的謂v.用一般現在時或現在完成時；從句的謂v.用一般過去時,而且須是終止性動詞.
(5)用於句型“一段時間 + has passed since + 時間狀語從句”中,譯作“自從…以來,…
(時間)已經過去了”.如上個例句還可寫成：Three months has passed since he moved to this city.
要求：主句的謂v.用現在完成時,而且動詞必須是has passed；從句的謂v.用一般過去時,而且須是終止性動詞.
since的用法：譯作“自從…以來”
(1)接時間點：如 I have stayed in that country since 1995.
要求：謂v.用現在完成時,而且須是延續性動詞.
(2)接一段時間 + ago：如 They have lived in that house since two years ago.
要求：謂v.用現在完成時,而且須是延續性動詞.
(3)接時間狀語從句：如 I have loved her since I met her last time./ Lily has stayed at home since she left school.
要求：主句的謂v.用現在完成時,而且須是延續性動詞；從句的謂v.用一般過去時,而且須是終止性動詞.
(4)用於句型“It’s / It has been + 一段時間 + since + 時間狀語從句”中,譯作“自從…以來,已經…(時間)了”.如 It’s / has been three months since he moved to this city.
要求：主句的謂v.用一般現在時或現在完成時；從句的謂v.用一般過去時,而且須是終止性動詞.
(5)用於句型“一段時間 + has passed since + 時間狀語從句”中,譯作“自從…以來,…
(時間)已經過去了”.如上個例句還可寫成：Three months has passed since he moved to this city.
要求：主句的謂v.用現在完成時,而且動詞必須是has passed；從句的謂v.用一般過去時,而且須是終止性動詞.