먹여야

In a sentence

• 아기가 배고파서 엄마가 아기에게 밥을 먹여야 합니다.

  The baby is hungry, so the mother needs to feed the baby.

  Here, '먹여야' is used to express the necessity ('you have to') of feeding someone ('먹이다' is the causative form of '먹다').

• 동물을 키우는 사람은 매일 먹이를 먹여야 해요.

  People raising animals need to feed them daily.

  In this sentence, '먹여야' is employed to denote the requisite action of feeding ('먹이다').

• 강아지는 아직 어리기 때문에 먹이를 먹여야 해요.

  Since the puppy is still young, it needs to be fed.

  Here, '먹여야' indicates the obligation to carry out the action of feeding someone ('먹이다').