"The lion is big."
So this sentence can't take 'הוא ' ?
Is this because it is a noun- adjective sentence? And are the following two sentences correct?
האריה הוא חיה גדול
זה הוא האריה הגדול
It doesn't require a הוא because it's a noun-adjective sentence. You can say האריה הוא גדול but you don't have to. They mean the same thing.
You can say האריה הוא חיה גדולה. Notice the interesting thing that happens here! אריה is male but חיה is female. גדולה is an adjective attached to חיה so agrees with it in gender. But the copula agrees with the אריה. That is because, in a noun = noun sentence, especially when using a pronoun as a copula (זה copulas work a little differently), the first noun is considered the subject, and the copula agrees with it. If I asked you, what is that big animal? You could say: החיה הגדולה היא אריה.
You can say זה הוא האריה הגדול. Usually, זה הוא contract to make זהו. You can write: זהו האריה הגדול.
Hi, I pretty much can say that in Spoken language we use more in "הוא" and it's equivelent somehow to the verb be in English.
no, but it can be האריה הוא גדול, since אריה is masculine. There is no neutral gender in Hebrew.