fish...deer...etc. uncountable nouns
I'm sorry for asking some stupid questions sometimes, but what embarrasses me the most is that I usually write very grammatically complicated sentences, yet I make silly mistakes.
When I speak about fish or deer , what pronouns should I use to refer to ( it / them )?
If they are both used, which one is academical?
And if there is one fish, can I say ( a fish )?
Thanks in advance.