In English, this would be a very strange thing to say. Difficult or easy maybe...
This is a weird way to say it. A language can be popular or less popular or spoken by many or few but we don't say that a language is either big or small.
What is meant by that?
I think they mean is it spoken by many or few people but you get to work with the vocabulary you've learnt so far. I'm not sure whether this has an obvious meaning in Finnish but it sure sounds awkward in English.
Is this language thin or thick? Wet or dry? Smooth or shaggy? Get ready for such questions, guys! )