Is “Half” singular or plural

Typically, if the subject is singular, the verb is singular. If the subject is plural, the verb is plural. But sentences that start with half don�t follow this rule.

we say: My half of the house is downtairs.  

but

we also say: Half of our expenses are bank credits.

Follow the rule:

 If half is followed by a singular noun, use a singular verb. If half is followed by a plural noun, use a plural verb. Half of the piza is gone, but half of the tomatoes are still half-cooked.