What about חתלתול?
That would be translated as kitten.
I think that's what I tried: חתולה קתנה. It told me it was a typo and gave the masculine form. Oh! I used the wrong "t". Gets me every time!
It's an adjective exersise, so I think it's implied that small cat should be used, not kitten
Wouldn't this translate as "A cat is little" since "A little cat" should be חתול הקטן?
No, חתול הקטן doesn't work, it doesn't translate to that. It goes like this:
A small cat - חתול קטן
A cat is small - חתול הוא קטן
The cat is small - החתול קטן
The small cat - החתול הקטן
male cat version with audio: https://forum.duolingo.com/comment/19169158
Why not הקטן?
Because it's not "the small cat".
If there is no "the" in English, there won't be ה in Hebrew.