紛らわしい語のペア

Confusing Word Pairs in Japanese

Even at C1 level, certain Japanese word pairs cause persistent confusion. Understanding the subtle differences is key to natural expression.

わけだ vs はずだ: Both express logical conclusions, but differently. わけだ states a logical consequence of known facts ("so it means that"), while はずだ expresses an expectation based on reasoning ("it should be").

3年も住んでいるなら、日本語が上手なわけだ。

*If you have lived there 3 years, it makes sense your Japanese is good.*

3年も住んでいるなら、日本語が上手なはずだ。

*If you have lived there 3 years, your Japanese should be good.*

は vs が (advanced): At C1, the distinction becomes nuanced. は marks known/contrastive information; が marks new/focused information or exhaustive listing.

田中さんは来ました。(As for Tanaka, he came.)

田中さんが来ました。(It was Tanaka who came.)

Master these pairs by paying attention to what information is new vs known, and whether you are stating facts or expectations.