よ
ENSentence-final assertion / new-information particle
JA「〜よ」(つたえる)
Explanation
よ at sentence-end conveys new information to the listener or emphasizes a point. 'I'm telling you / you should know'.
Examples
JAあした しけんですよ。
ENThere's an exam tomorrow, you know.
JAそれは ちがいますよ。
ENThat's wrong (let me tell you).
JAおいしいですよ、たべてみてください。
ENIt's delicious - try it.
JAあぶないですよ。
ENIt's dangerous!
JAそっちは あぶないですよ。
ENThat way is dangerous.
JAがんばってくださいよ。
ENPlease do your best, you know!
JAこれ、おいしいですよ。
ENThis is tasty, you know!
JAこれは おいしいですよ。
ENThis is tasty (you should know).
JAもう おそいですよ。
ENIt's already late (you should know).
JAやまださんは げんきですよ。
ENYamada-san is well (you should know).
Common mistakes
✗ みなさんに よろしく おねがいしますよ。
✓ みなさんに よろしく おねがいします。
よ adds a chatty, FYI-style tone. In formal written contexts (business emails, reports, official messages) drop よ for a neutral, professional register. よ stays appropriate in casual speech or messaging where you are informing the listener of new information.
✗ あした しけんですよか。
✓ あした しけんですよ。
よ stands alone at sentence-end as an assertion particle ('FYI, just so you know'). Don't stack か after よ — that creates a question, which contradicts よ's role of asserting NEW information to the listener.
Register variants — both forms are correct
These forms differ in register, formality, or pragmatic context — not in grammaticality. Pick by context.
Seeking agreement (ね) あした しけんですね。
Informing (よ) あした しけんですよ。
ね seeks agreement; よ informs the listener of something they may not know. Both correct - choose by intent.
Wrong / corrected pairs
✗ よ たかいです。
✓ たかいですよ。
よ is a sentence-final particle; attach it at the very end (after です), not at the start.
✗ がくせいよ です。
✓ がくせいですよ。
よ goes at the very end of the sentence, after です.
✗ たべますよか。
✓ たべますか。 / たべますよ。
Cannot stack よ + か. They serve different functions (assert vs question).