CONDITIONAL SENTENCES- Alternatives to IF

Many  words and expressions can be used  with similar meanings to IF and  often with similar structures

·        Unless + affirmative verb = if + negative

     Unless you start at once  you'll be late = If you don't start at ......

Note the difference between :

a)     Don't call me  if you need help

b)     Don't call me unless you need help

·        Provided (that)/Providing That

  Can replace If  when there is a strong idea of limitation or restriction . It is chiefly used with permission.

    You can camp here provided  you leave no mess

    You can borrow my car provided you   fill the tank

·        In case

 It's followed by a present or past tense or by should. It is completely different from  If. It gives a reason for the action in the main clause

Some cyclist carry repair outfits in case  they have a puncture (Because they may have...)

I always slept by the phone in case he rang during the night . (because he might ring...)

An In case clause can be dropped without changing the meaning of the main clause. Compare:

I´ll come tomorrow in case Ann wants me

I´ll come tomorrow if Ann needs me.

·        As long as    = on condition that

You can take my car as long as you drive carefully  (on condition that you drive...)

·        Even  if = adds emphasis to IF

My parents would never let me have a motorbike even if I paid for it