시는

In a sentence

• 그 시는 아주 유명해요.

  That poem is very famous.

  In this sentence, '시는' is used as the subject particle for the noun '시' meaning 'poem'.

• 부모님께서는 아침에 산책을 하시는 편이에요.

  The parents tend to take a walk in the morning.

  Here, '시' is part of the honorific verb form '하시다', indicating respect toward the subject performing the action.

• 서울시는 대중교통이 편리해요.

  The city of Seoul has convenient public transportation.

  In this context, '시는' follows '서울시', here referring to 'the city of Seoul', acting as the subject particle for the proper noun.