Questions & Answers about Если банан уже мягкий, он обычно слаще, чем груша.
In Russian, the present-tense form of to be is usually omitted.
So:
- банан мягкий = the banana is soft / a banana is soft
- он обычно слаще = it is usually sweeter
This is completely normal. Russian only uses forms of быть more visibly in the past, future, or in certain special constructions.
Russian does not have articles.
So банан can mean:
- a banana
- the banana
- sometimes just banana in a general sense
You understand which one is meant from context. In this sentence, English might say a banana or the banana, but Russian simply says банан.