неинтересное

In a sentence

• У меня есть книжка, которая показалась мне неинтересной.

  I have a book that seemed uninteresting to me.

  Here, 'неинтересная' is used as an adjective in its feminine singular form to describe the noun 'книжка' (book). It conveys that the speaker did not find the book engaging.

• Он рассказал неинтересную историю, и слушатели начали засыпать.

  He told an uninteresting story, and the listeners began to fall asleep.

  The word 'неинтересную' is used as an adjective in its feminine singular accusative form, modifying the noun 'история' (story). It indicates that the story lacks intriguing content.

• Я думал, что фильм будет захватывающим, но он оказался неинтересным.

  I thought the movie would be captivating, but it turned out to be uninteresting.

  The word 'неинтересным' is an adjective in its masculine singular instrumental case, modifying 'фильм' (movie), declaring the speaker's disappointment about the movie's quality.