Questions & Answers about Druga soba je mala.
Because soba is a feminine singular noun, and Serbian adjectives must agree with the noun in gender, number, and case.
So here:
- druga = feminine singular
- soba = feminine singular
- mala = feminine singular
That is why all three match.
Compare:
- drugi sto je mali = the second table is small
- drugo selo je malo = the second village is small
Je means is. It is the 3rd person singular present form of biti = to be.
So:
- ja sam = I am
- ti si = you are
- on/ona/ono je = he/she/it is
In Druga soba je mala, je links the subject druga soba with the description mala, just like is in English.
Because je is a clitic in Serbian. Clitics usually go in the second position of the sentence or clause, not necessarily after the first single word.