used to + do:"過去常常"表示過去習慣性的動作或狀態(tài),但如今已不存在。
Mother used not to be so forgetful.
Scarf used to take a walk. (過去常常散步)
be used to + doing: 對……已感到習慣,或"習慣于",to是介詞,后需加名詞或動名詞。
He is used to a vegetarian diet.
Scarf is used to taking a walk.(現(xiàn)在習慣于散步)
典型例題
---- Your phone number again? I ___ quite catch it.
---- It's 69568442.
A. didn't B. couldn't C. don't D. can't
答案A. 本句雖沒有明確的時間狀語,但從語意上看 出,在聽的時候沒有聽懂這個動作發(fā)生在過去,因此應用過去時。