Hello there Woojung,

Thank you for submitting your homework. Please take notes of my corrections. See you in our class..

Corrections:

I think hobbies are important to people beacuse it makes people happy when they are sad.

Correct: I think hobbies are important to people because they make people happy when they are sad.

** 'Hobbies' is a plural noun which requires an equivalent pronoun subject 'they', which then requires a plural verb 'make'.

Hobbies are great thing and give many happiness to people.

Correct: Hobbies are great things. They give much happiness to people.

**'Many' is a partial word used for countable nouns, while 'much' is for noncountable nouns; 'happiness' is abstract and cannot be counted. Also, It is better to just split your complex sentence into two, since there are two different sentence pattern in each sentence.

Everyone should have least 1 hobbies because it will help them to be happy again when they are not well, feel bad.

Correct: Everyone should have at least one hobby because it will help him to be happy again when he is not well, or when he feels bad.

** 'Least' is an adjective which means 'smallest in size, amount, or degree'. But in the sentence, it would have been better to use an idiom 'at least' meaning 'at the lowest estimate or figure'. Both may quite be similar, but the function of the words in the sentence is important. And because the numerical adjective used is 'one', then the noun following it should be singular; so instead use 'hobby'. Words like "everyone" and "everybody" are always singular, so the plural pronoun their can't agree with them; thus, it's better to use 'him' than 'they'.

 Hobbies are important for people's lives everytime.

Correct: Hobbies are important to people's lives every time.

**'For' is used when you say something is 'intended to belong to, or be used in connection with'. 'To', in the other hand, is used for expressing the object of a right or claim.