To give advice to someone we can use the expression 方がいいです, meaning had better or should do.
方がいいです is used at the end of the sentence, and it follows different tenses depending on whether the advice is in the affirmative or negative, i.e. had better or had better not.
When giving advice in the affirmative, 方がいい follows a verb in the plain past tense.
It's nearly time. You should go. | そろそろ 時間 です。 行った 方 が いい です。sorosoro zikan desu. itta hou ga ii desu. |
You should get more sleep! | もっと 寝た 方 が いい です よ。motto neta hou ga ii desu yo. |
Have you caught a cold? You should take some medicine. | 風邪 を 引いた んです か。 薬 を 飲んだ 方 が いい です。kaze wo hiita ndesu ka. kusuri wo nonda hou ga ii desu. |
For advice in the negative, use the verb in the plain present tense.
It's raining. You shouldn't go. | 雨 です。 行かない 方 が いい です。ame desu. ikanai hou ga ii desu. |
方がいいです can also be written in hiragana rather than kanji as ほうがいいです, and in informal situations you can omit the final です.
You shouldn't miss work. | 仕事 を 休まない ほう が いい。sigoto wo yasumanai hou ga ii. |
You should eat more salad. | もっと サラダ を 食べた 方 が いい。motto sarada wo tabeta hou ga ii. |