4.1 used to是用来描述过去习惯性的或反复发生的动作。否定式可以由used not to 或didn’t use to 构成，never也可以用于构成否定式。
(1) When I was younger, I used to cycle to work, but I don’t now. 我年轻的时候常常骑自行车上班，但是现在不骑了。
(2) My brother used not to come to the fair with us.
(3) My brother didn’t use to come to the fair with us.
(4) My brother never used to come to the fair with us. 我哥哥过去不曾和我们一起去游乐场。
4.2 used to 可以与状态动词连用，表示曾经一度怎样。 (1) I used to like the fair. 我曾经喜欢（去）游乐场。 (2) My friends used to like him. 我的朋友们曾都喜欢着他。 (3) We used to live near a big park. 我们曾经住在一个大公园附近。
4.3 would加上动词原形可以用来描述过去习惯性的或反复发生的动作。否定式由would + not 构成， 常和ever 连用。would 在表示过去的习惯时不可与状态动词连用。
(1) When I was younger, I would cycle to work, but I don’t now. 我年轻的时候，常常骑车上班，现在不了。 (2) Then we would go up to my bedroom and listen to pop. records. 然后我们总是会上楼到我的卧室里听流行唱片。(3) My brother wouldn't ever come to the fair with us. 我哥哥过去从来不与我们一起去游乐场。