Is could a contraction?
no it's not
What is the contraction for it is?
it'sI also found a full list of contractions if you need it:http://www.enchantedlearning.com/grammar/contractions/list.shtml
What is the contraction of we are?
What is contraction for you had?
What is the contraction of he has?
There is no contraction for 'he has.'