used

音標(biāo)發(fā)音

adj性質(zhì)的同根詞
usable：可用的；合用的（等于useable）。
useful：有用的，有益的；有幫助的。
useless：無(wú)用的；無(wú)效的。
useable：可用的；便于使用的（等于usable）。
adv性質(zhì)的同根詞
usefully：有效地，有用地。
uselessly：無(wú)用地；無(wú)益地。
n性質(zhì)的同根詞
usage：使用；用法；慣例。
use：使用；用途；發(fā)揮。
using：使用；利用。
user：用戶；使用者。
usefulness：有用；有效性；有益。
usability：合用，可用；可用性。
usableness：可用；使用方便。
uselessness：無(wú)用，無(wú)效。
v性質(zhì)的同根詞
using：使用（use的ing形式）。
vi性質(zhì)的同根詞
use：使用，運(yùn)用。
vt性質(zhì)的同根詞
use：利用；耗費(fèi)。

used與介詞to連用,表示“習(xí)慣于…的”,在句中一般用作表語(yǔ),其后只能接名詞、代詞、動(dòng)名詞,不能接動(dòng)詞不定式。如強(qiáng)調(diào)由不習(xí)慣到習(xí)慣,須用get或become而不能用be。

shows that a particular thing always happened or was true in the past, especially if it no longer happens or is no longer true
(FAMILIAR) to be familiar with something or someone
(NOT NEW) that has already been put to the purpose it was intended for; not new

If something used to be done or used to be the case, it was done regularly in the past or was the case in the past.
If something did not use to be done, used to not be done or used not to be done, it was not done in the past.
If you are used to something, you are familiar with it because you have done it or experienced it many times before.
If you get used to something or someone, you become familiar with it or get to know them, so that you no longer feel that the thing or person is unusual or surprising.
A used object is dirty or spoiled because it has been used, and usually needs to be thrown away or washed.
A used car has already had one or more owners.