筈だ
Bound to (be), Expected to (be), Should be (able)
Structure
［い］Adjective + はず + だ
［な］Adjective + な + はず + だ
Noun + の + はず + だ
Explanation
はず, which can be written with the kanji 筈, expresses a strong expectation based on logic or evidence. It conveys that the speaker feels something is almost certainly true, but they don't have absolute proof. Common English translations include 'it's supposed to be (A)', 'it should be (A)', and 'I expect (A)'.
Grammatically, はず functions as a noun, so it connects to other words just like a noun does. For this reason, it is frequently followed by the copula だ or です.
- 会議は10時に始まるはずだ。The meeting is supposed to start at 10 o'clock. (But plans might have changed)
- あのレストランは美味しいはずだ。That restaurant is bound to be delicious. (But I haven't personally tried it)
- 彼は毎日運動しているから、元気なはずだ。Since he exercises every day, he should be healthy. (But I can't know for certain if he is)
- 注文したのはピザのはずだったのに、パスタが届いた。I was sure that I ordered a pizza, but pasta arrived. (But I might have misclicked)
Caution
While はず is often translated as 'should', it only applies to expectations of what 'should be true'. It cannot be used for giving advice or making suggestions. To avoid confusion, it's often better to think of 筈 as meaning 'I expect' or 'it's supposed to be' in most cases.
Fun Fact
Dropping the final だ (or です) after はず is quite common. This can make the statement sound softer or a bit less conclusive, similar to adding '...I think' in English. When used by itself at the end of a sentence fragment, はず can function much like 多分 (probably), indicating that the speaker isn't entirely sure about what they've just said.
- 田中さんはオフィスにいる…はず。Mr. Tanaka is in the office… I think.
- 出かける前にドアに鍵をかけた… はず。I locked the door before I left… I'm pretty sure I did.
Examples
彼は一生懸命勉強したから、試験に合格する筈だ。
He studied very hard, so he is expected to pass the exam. (bound to)
このレストランは有名だから、美味しい筈だ。
This restaurant is famous, so it should be delicious. (bound to be)
この鍵を使えば、ドアを開けられる筈だ。
If you use this key, you should be able to open the door. (bound to)
鞄に財布を入れたから、中にある筈だ。
I put my wallet in my bag, so it is bound to be inside. (expected to be)
荷物は今日届く筈だ。
The package is supposed to arrive today. (expected to)
会議は三時の筈です。
The meeting is supposed to be at three o'clock. (expected to be)
彼はスポーツが上手だから、人気な筈だ。
He's good at sports, so he is bound to be popular. (expected to)
今日は休みの筈だったのに、会社から電話があった。
It was supposed to be my day off, but I got a call from work. (expected to be)
こんな難しい問題は、子供には解けない筈だ。
A child shouldn't be able to solve such a difficult problem. (bound to・expected to)
この薬を飲めば、すぐに効く筈だ。
If you take this medicine, it is expected to work soon. (bound to)
姉は近くに住んでいるから、手伝ってくれる筈だ。
My older sister lives nearby, so she should be able to help. (bound to・expected to)
ちゃんと鍵をかけた筈だったのに、ドアが開いていた。
I was sure I had locked the door, but it was open. (expected to)