uusi

In a sentence

• Ma ostsin täna poest uusi kingi.

  I bought new shoes from the store today.

  Here, 'uusi' is the partitive plural form of the adjective 'uus' (new), agreeing with 'kingi' (shoes) that is in the partitive plural case since it's the object of buying in an indefinite sense.

• Tal läks vaja uusi raamatuid.

  They needed new books.

  In this sentence, 'uusi' is again the partitive plural form of 'uus,' corresponding to 'raamatuid' (books) in the partitive plural, as it's indicating an indefinite requirement.

• Meil on vaja uusi ideid projekti jaoks.

  We need new ideas for the project.

  Here, 'uusi' follows the same grammatical rule, being partitive plural to match 'ideid' (ideas), which is partitive plural as the object of needing.