N5
たほうがいい
It'd be better to, Should do
食べる前に手を洗った方がいいよ。
You should wash your hands before you eat.
Explanation
「〜たほうがいい」 is advice, 'you had better …': 「薬を飲んだほうがいいですよ」 (You should take some medicine). It compares 'doing it' with 'not doing it' and says the first is better. It is common among friends, from a doctor to a patient, and between peers. The polite form is 「〜たほうがいいです」.
Mixed up with
For advice to someone, the verb usually takes the た-form: 「〜たほうがいい」. The dictionary form (「片付けるほうがいい」) is also used for general statements, but in exams pick the た-form for advice.
Advice carries the tone 'I know what is good for you', so do not say 「〜たほうがいいです」 straight to a boss or an elder; to offer an opinion upward use 「〜てはいかがでしょうか」.
In speech 「が」 is often dropped: 「〜たほういい」.