unless

unable / incapable

uncertain / unsettled

understandable understanding

unimportant / petty / trifling

university / college

unkind / mean / nasty

unless / if...not

until / to / up to /
as far as

update / upgrade /
up-to-date /
up-to-the-minute

upside down /
inside out / backward

U.S.A. / U.S. / America / the States

usage / use

used to / would


	unless / if...not

A.	unless는 또 다른 행위나 상황에 따라 바뀌는 행위나 상황에 대하여 말하고자 할 때 사용되며 ...하지 않으면, ...하지 않는 한 이라는 의미로 사용된다..
1.	I won't go unless you do.
2.	I can't take your picture unless you keep still.
3.	I won't talk to her unless she apologizes.
4.	Unless he agrees, we have no contract.
5.	We shall go unless it rains.
6.	Don't call me at the office unless it's absolutely necessary.
7.	Unless you are a military fan, the Pentagon tour isn't very exciting.
8.	Unless the doctors operate immediately, she'll die.
9.	Unless he's a complete idiot, he'll understand.

	unless절에서 부정어는 사용되지 않는다.
	1. You can't get in unless you don't have a key. (x)
	2. You can't get in unless you have a key. (o)
	3. You can't get in if you don't have a key. (o)

B.	if...not은 발생하지 않았거나 여러분이 알고 있는 것이 맞지 않을 때 사용되며 만일 ...하지 않았더라면, 만일 ...하지 않다면 라는 의미로 사용된다.
1.	She would have died if the doctors hadn't operated immediately.
2.	If Tom weren't so stupid, he would understand.

C.	unless와 if...not이 서로 같은 의미로 쓰이는 경우는 가정이 아닌 어떤 조건이 아니면 이라는 의미를 나타내는 현재나 미래의 조건을 나타낼 때이다.
1.	Unless Tom comes soon, I'm going without him.
2	If Tom doesn't come soon, I'm going without him.

You can't get in unless you have
a key.

Unless the doctors operate immediately,
she'll die.

If Tom weren't so stupid, he would understand.

Unless Tom comes soon, I'm going without him.