Unless

Question

Hello teachers! Would you please explain the usage of the word "unless". Thanks.

CalifJim · Accepted Answer

Hanuman_2000 · Answer

Sir,

That is about "until" vs " by the time".

Is until=unless

Thanks.

CalifJim · Answer

Hanuman,

Surely you can find the parts of that post that apply to "until"!

CJ

Paco2004 · Answer

You can think is almost equal to .
Tomorrow we'll go to a picnic unless it rains
= Tomorrow we'll go to a picnic if it doesn't rain.

However there are some subtle differences between and .
I think you can learn them in details here from our teachers.

paco

[PS]Visit:[url="http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv272.shtml"]BBC English 'Unless'[/url] if you like.

Paco2004 · Answer

(1) If X does not happen, Y will happen = Y will happen when X does not happen.
(2) Unless X happens, Y will happen.= Y will be prevented to happen only when X happens.
Sometimes (1) happens to be equal to (2) but not always.

1. If you don't take an umbrella, you'll get wet.
(OK) Unless you take an umbrella, you'll get wet.
2. If you don't have an umbrella, I'll lend you mine.
(?) Unless you have an umbrella, I'll lend you mine.
3. He'll fail his exam if he doesn't study hard.
(OK) He'll fail his exam unless he studies hard.
4. I'll be very disappointed if he doesn't study.
(?) I'll be very disappointed unless he studies.
5. They won't let you in if you don't wear a tie.
(OK) They won't let you in unless you wear a tie.
6. Will it be all right if I don't wear a tie?
(?) Will it be all right unless I wear a tie?
7. If it doesn't rain this August, there will be water shortages.
(OK) Unless it rains this August, there will be water shortages.
8. If it doesn't rain in August the tourists will be happy.
(?) Unless it rains in August the tourists will be happy.
9. In the old days people never traveled if they didn't really have to.
(OK) In the old days people never traveled unless they really had to.
10. You'd sleep better if you didn't drink coffee before bed.
(?) You'd sleep better unless you drink coffee before bed.

paco

Anonymous · Answer

0 Hi!02br
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00Is it wrong to use "unless" with if-clauses type 2 and type 3? If yes, why?02br
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00Thank you02br
02br
00Ana01blockquote

01cite10Paco200412cite10(1) If X does not happen, Y will happen = Y will happen when X does not happen. 12br
10(2) Unless X happens, Y will happen.= Y will be prevented to happen only when X happens. 12br
10Sometimes (1) happens to be equal to (2) but not always. 12br
12br
10 1. If you don't take an umbrella, you'll get wet. 12br
10 (OK) Unless you take an umbrella, you'll get wet. 12br
10 2. If you don't have an umbrella, I'll lend you mine. 12br
10 (?) Unless you have an umbrella, I'll lend you mine. 12br
10 3. He'll fail his exam if he doesn't study hard. 12br
10 (OK) He'll fail his exam unless he studies hard. 12br
10 4. I'll be very disappointed if he doesn't study. 12br
10 (?) I'll be very disappointed unless he studies. 12br
10 5. They won't let you in if you don't wear a tie. 12br
10 (OK) They won't let you in unless you wear a tie. 12br
10 6. Will it be all right if I don't wear a tie? 12br
10 (?) Will it be all right unless I wear a tie? 12br
10 7. If it doesn't rain this August, there will be water shortages. 12br
10 (OK) Unless it rains this August, there will be water shortages. 12br
10 8. If it doesn't rain in August the tourists will be happy. 12br
10 (?) Unless it rains in August the tourists will be happy. 12br
10 9. In the old days people never traveled if they didn't really have to. 12br
10 (OK) In the old days people never traveled unless they really had to. 12br
10 10. You'd sleep better if you didn't drink coffee before bed. 12br
10 (?) You'd sleep better unless you drink coffee before bed. 12br
12br
10paco12blockquote

10 0-

Unless

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