Korean grammar - To need and to not need - 필요 있/없다 & 필요하다

To need and to not need - 필요 있/없다 & 필요하다

The pattern Verb stem + ㄹ/을 필요 없어요 means 'to have no need to' or 'to not need to'.

The inverse Verb stem + ㄹ/을 필요 있어요 is less common - better to use 해야 하다.

-- The subject marker 가 is often attached to 필요.

When referring to whether a noun is needed we can use the verb 필요하다.

Examples:
	물을 더 마실 필요가 있어요. (I) need to drink more water.
	고양이에게 먹이를 줄 필요가 있어요? Do (I) need to feed the cat?
	필요 없어요. No need to.
	이젠 할 필요가 없어요. There's no need to do (it) now.
	안경을 쓸 필요가 있어요. (I) need to wear glasses. 쓰다 means 'to use' or 'to wear' The verb 쓰다 is used to say 'to wear glasses'
	집에 가기 전에 그걸 끝낼 필요가 있었어요. Before (I) went home (I) needed to finish that. Could better say: ...끝내야 했어요.
	날씨가 좋아서 우산을 가져갈 필요가 없어요. The weather is fine so there is no need to take an umbrella.
	날씨가 좋아서 우산을 가져갈 필요가 없었어요. The weather was fine so there was no need to take an umbrella.
	여기에 오기 전에 전화를 할 필요가 없었어요. It was not necessary to call before (you) came over.
	그녀에게 소리칠 필요가 없었어요. There was no need to yell at her.
	이 식당에는 예약할 필요가 없어요? Don't (you) need to make a reservation for that restaurant?
	사과할 필요가 없어요. There’s no need to apologise.
	서울역에서 갈아탈 필요가 없어요. There’s no need to transfer at Seoul Station.
	서두를 필요가 없어요. There’s no need to hurry.
	그렇게 멀리까지 갈 필요가 없어요. There’s no need to go that far.
	제 운동화가 필요해요? Do (I) need my trainers?
	살이 빠져서 새 옷이 필요해요. Because (I) lost weight (I) need new clothes. 살이 빠지다 means 'to lose weight'
	스위스에서 생활할 위해 돈이 얼마나 필요해요? How much money is needed to live in Switzerland?
	책이 몇 권 필요해요? How many books do (you) need?
	생각할 시간이 필요해요. (I) need time to think.