condition/concession

[ruofei]

Dear teachers,
I can't really figure out the difference between "as long as" and "unless"
Could you help me with this, please?
If I take this example:

You can drive my car unless/as long as you drive carefully.

I feel that both could work, couldn't they?
Or maybe either brings a new meaning...

Which rule should I keep in mind to distinguish between the 2?

Thanks in advance!

[Steven D]

Dear teachers,
I can't really figure out the difference between "as long as" and "unless"
Could you help me with this, please?
If I take this example:

You can drive my car unless/as long as you drive carefully.

I feel that both could work, couldn't they?
Or maybe either brings a new meaning...

Which rule should I keep in mind to distinguish between the 2?

Thanks in advance!

They're both correct, but the meaning changes depending on which one you use. If you use "unless", then you should logically use "can't", not "can" in this sentence.


You can drive my car unless/as long as you drive carefully.

unless you drive carefully = if you don't drive carefully

You can't drive my car unless you drive carefully. = You can't drive my car if you don't drive carefully. = If you want to drive my car, you have to drive carefully. = You can drive my car, but you have to drive carefully.

as long as = if - with the the condition - provided

You can drive my car as long as you drive carefully. = You can drive my car if you drive carefully. You can drive my car only if you drive carefully.

[ruofei]

Thank you very much X-Mode
I couldn't have expected a better explanation! :) :)
Best regards,
Ruofei.

[Steven D]

Thank you very much X-Mode
I couldn't have expected a better explanation! :) :)
Best regards,
Ruofei.

You're welcome.

[Steven D]

Thank you very much X-Mode
I couldn't have expected a better explanation! :) :)
Best regards,
Ruofei.

It's good to keep in mind that "unless" means "except if".

Here's another example:

You should bring a sweater unless you don't think you'll need one. Then, of course, don't bring one. = You shouldn't bring a sweater unless you think you'll need one. = You shouldn't bring a sweater if you don't think you'll need one.

unless you think you'll need one = if you don't think you'll need one

unless you don't think you'll need one - The exception to bringing a sweater is that you don't think you'll need it. - Don't bring a sweater unless you think you'll need one.

We should leave at 8 unless you think it's okay to leave a little later. = We can leave a little later if you think it's okay.

unless you think it's okay to leave a little later - The exception is that you think it's okay to leave a little later. - We don't have to leave at 8 if you think it's okay to leave a little later.

http://dictionary.cambridge.org/defi...6732&dict=CALD

unless - except if

Lissa Explains it All -- How to Copyright
... I wouldn't use frames unless you think it's absolutely necessary. up. How do
I get more hits? Getting more hits to your site can be very difficult. ...
www.lissaexplains.com/basics3.shtml - 23k - Cached - Similar pages

[ruofei]

It's good to keep in mind that "unless" means "except if".

Here's another example:

You should bring a sweater unless you don't think you'll need one. Then, of course, don't bring one. = You shouldn't bring a sweater unless you think you'll need one. = You shouldn't bring a sweater if you don't think you'll need one.

You see X-Mode,
your first explanation was so clear that 1) I understood straightaway the difference between both conjunctions and 2) what you're telling me now is exactly the way I decided to translate into French (except if= 'sauf si')

You can't drive my car unless you drive carefully =
You cannot drive my car if you don't drive carefully =
You can drive my car except if you don't drive carefully

As you said, there's always a negative statement/understatement mentionned somewhere.

Thank you again X-Mode, very much