Learn Swedish: Vi trodde att bandet spelade falskt. - We thought that the band played out of tune.

In this sentence, the word describes how the band played, which means it acts as an adverb. In Swedish, you normally create an adverb by adding -t to the end of a base adjective, changing falsk to falskt.

Does falskt literally mean out of tune?

The adjective falsk literally translates to false or fake. However, when used in the context of music, singing, or playing an instrument, it is the standard Swedish way to say out of tune or off-key.

Why is the past tense of tro spelled as trodde with a double D?

The base verb tro (to believe or think) ends in a vowel. In Swedish, short root verbs that end in a stressed vowel usually form their past tense by adding -dde rather than the regular -de or -te.

Where would I put inte if we thought the band did not play out of tune?

You would say: Vi trodde att bandet inte spelade falskt. Because att bandet inte spelade falskt is a subordinate clause (a dependent sentence introduced by att), the word inte must come before the verb spelade.