why don't we use han instead of hay?
if in english you say there is a lot of pollution, - hay mucha contaminación
and for the plural you use there are, for example there are lots of factories, - hay muchas fábricas... why don't you use han instead of hay?
1 Answer
The word "hay" as used here is the impersonal form of the verb haber, and in this context it means "to exist, to be". The word "han" is the present perfect form of the auxillary verb haber meaning "they have" completed something (han salido, they have left), so in this context it wouldn't make any sense.