Many words end in the suffixes -ible and -able, and it is often hard to know which spelling to use.
For example, why is it probable but possible?
In fact, words ending in -able are far more common than ones ending in -ible, so if you are not sure, then it is best to use -able.
Here is a list of common words that do end in -ible. It is a good idea to learn them. (There are some more, but they are not as common.)
visible (and invisible)
possible (and impossible)
Maybe you could try making up some silly sentences to help you to learn these -ible words!
How about: It is impossible for my terrible sister to be sensible or responsible.
It is possible for toadstools to be edible but they could still be horrible.
Note that the fly agaric toadstool above is not edible!!
Why not have a go at making some of your own?
In this worksheet you can practise spelling words ending in -ible and -able.