"V mém pokoji byl jen stůl s jednou židlí."

Translation: In my room, there was only a table with one chair.

[VladimirBa867678]

In my room, was only a table with one chair. špatně?

[realberggren]

Duo counts it wrong because it wants the word "there" in the sentence. With a different word order, you wouldn't have left it out - There was only a table with one chair in my room.

[VladaFu]

Indeed, see the correct form above.

[strubkin]

Was or were? Table plus chair.

[VladaFu]

http://guidetogrammar.org/grammar/sv_agr.htm point 3