I 'd like to cancel my reservation.

我想取消预约。

原则上虽然would是will的过去式，但在与like to 配搭使用时没有过去式的意义。
would like to若是使用来表达一个要求，绝对是个一定的搭配，不能用“will like to”。would like to是want to的较有礼貌、正式的说法。由于want to听起来即没有礼貌又很苛求，大致上在与陌生人谈话的时候，或是对公司会员表达某种要求是，都使用would like to比较适宜。

'd此后缀不仅代表would，其实也代表had。

例：

He'd better watch out! Once I see him on the streets, I'll make sure he'll be beaten up into a pieces!
= He had better...
他最好给我小心点儿！若他让我在路上看见他，我一定非把他打成碎片不可！

Before Kate thought of buying a cake for herself, he'd baked a delicious cake specially for her.
= ..., he had baked...
在凯特想为自己买一个蛋糕前，他已经特别为她烘了一个美味的蛋糕。

I'd like to cancel my reservation. 此句可以在餐厅定位时想临时取消预定。只要是取消一种以预约的方式获得优先权，无论是座位、房间，都可以使用。