782 - はずだ (must [surely])

JLPT N4: はずだ (must [surely])

I'm not entirely sure why, but I was confused about how to use はずだ for the first year or so after I initially learned it.

Looking at it now, I can't really see why I was so confused by it. Maybe I was trying to learn too many ways to say "should" all at once. Speaking of which, we've seen some other "should" grammar patterns already:
- [NDL #470] - JLPT N4: ~たほうがいい
- [NDL #429] - JLPT N3: べきだ

Anyway, looking at はずだ with my more informed brain of today, it seems fairly straightforward:

Use はずだ when you are confident that something is a certain way based on some kind of objective observation.

In other words, it is used when conclusions about things seem natural. It will typically be translated to things like "must" or "must have," "should," "surely," etc.

An example:


春奈さんはもう帰ったはずですよ。駐車場に車がなかったから。
はるな さん は もう かえった はずです よ。 ちゅうしゃじょう に くるま が なかった から。
Haruna-san must have gone home already. Her car wasn’t in the parking lot.
Literally: “Haruna-san + は + already + returned home + はず + です + よ. + parking lot + に + car + が + there wasn’t + because.”

The speaker is fairly confident that Haruna-san has already gone home. This is based on an objective observation: Her car wasn't in the parking lot.


While the meaning of はずだ might make sense now (or by the end of this lesson, hopefully), the construction patterns are not quite as easy.

The simple version is that はずだ comes before a word in plain form:

Plain-Form Wordはずだ

However, when the plain-form word before はずだ is a na-adjective, it must be followed by な:

na-adjectiveはずだ

When the plain-form word before はずだ is a NOUN, it must be followed by

NOUNはずだ

Technically both of these could also be followed by である, too, but I don't think we need to worry about that.


All that's left to do now is to power through some examples...


通訳は大木さんにお願いしましょう。帰国子女だから英語が得意はずです
つうやく は おおき さん に おねがい しましょう。 きこくしじょ だ から えいご が とくいな はずです。
Let’s ask Ōki-san to interpret for us. He [She] used to live abroad, so he [she] must be good at English.
Literally: “interpretation + は + Ōki-san + に + request + let’s do. + a person who grew up in a foreign country + だ + から (=because) + English + が + skilled / strong point + はず + です.”


The speaker is confident that Ōki-san is good at English. This conjecture seems natural based on some evidence: Ōki-san has lived abroad before.



沙織ちゃんは、8月に会った時に妊娠7ヶ月だったのだから、もうお母さんはずだ
さおり ちゃん は、 はちがつ に あった とき に にんしん ななかげつ だった のだ から、 もう おかあさん の はずだ。
Saori-chan was seven months pregnant when I saw her in August, so she must be a mother now.
Literally: “Saori-chan + は, + August + に + met / saw + time / when + に + pregnancy + seven months + was + のだ + から (=because), + already + mother + の + はず + だ.”


The speaker is confident that her conjecture is accurate: Saori-chan must be a mother now. This conclusion is natural based on the fact that Saori-chan was seven months pregnant back in August.



阿部君はもう電車に乗ったそうですから、時間通りにここに来るはずです
あべ くん  は もう でんしゃ に のった そうです から、 じかん どおり に ここ に くる はずです。
Abe-kun said that he’s already on the train, so he should get here right on time.
Literally: “Abe-kun + は + already + train + に + boarded + そうです (=[hearsay marker]) + から (=because), + on time (=time + in accordance with) + に + here + に + come + はず + です.”


The speaker is confident that Abe-kun will arrive on time based on some evidence that strongly supports this conclusion: Abe-kun said that he's already on the train.


What do you think? Not too hard?

We're not done with はず just yet, as we still have two more grammar points to cover that contain it.

But hey... progress!




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