[Korean grammar] V-으세요/ 세요

여기 앉으세요.
Please sit here.

책 15쪽을 보세요.
Please see (look at) page 15 in the book.

이 길로 쪽 가세요.
Please go straight up this road.

Usage:
-(으)세요 is used when politely asking the listener to do something when making a request and when giving directions or orders. It corresponds to ‘please (do)’ in English. In such situations, -아/어요 can also be used, but -(으)세요 is more polite than -아/어요. When the verb stem ends in a vowel, -세요 is added, and when it ends in a consonant, -으세요 is added. Some verbs have special forms though. The formal polite style uses -(으)십시오.

When -(으)세요 is used in the imperative sense to give an order, it can only be used with verbs and not 이다 or adjectives.
• 의사이세요 (X) -> 의사가 되세요. (〇) Please become a doctor.
• 기쁘세요 (X) -> 기뻐하세요.(〇) Be happy.
(Adjective changed to its verb form)

However, there are a number of adjectives ending in used idiomatically that can be used with -으세요.
• 할아버지, 건강하세요. 오래 오래 사세요.
Grandpa, please be healthy. Live a long, long time.

• 민우 씨, 결혼 축하해요. 행복하세요.
Min-u, congratulations on your marriage. I wish you happiness.

Conversation:
A: 살을 빼고 싶어요.
I want to lose some weight.
B: 그럼 야채를 많이 드세요. 그리고 운동을 많이 하세요.
Then you should eat a lot of vegetables. And get lots of exercise.

A: 여기에 이름과 전화번호를 쓰세요.
Please write down your name and phone number here.
B: 알겠습니다. Okay.

A 여러분, 조용히 하세요! 자, 사장님, 말씀하세요.
Everyone, please be quiet! Now, Director, please begin (speaking).
B 고마워요, 김 부장
Thank you, Manager Kim.