Practice JLPTHow to tell them apart
Both point to a cause for a bad outcome, but ばかりに stresses that one single, often minor or unfair factor is the whole reason things went wrong, carrying a sense of "if only that hadn't happened." せいで simply blames a cause for an undesirable result and is commonly used to pin fault on someone or something, as in 誰のせいでもない. Swapping them feels off because ばかりに sounds too dramatic for a neutral blame statement, while せいで lacks the "just because of that one thing" nuance.
- ばかりに Use ばかりに when one small or specific factor alone triggers an unfortunate result.
- せい Use せいで when you want to blame a cause or someone's fault for a bad outcome.
| Grammar point | Meaning | JLPT level |
|---|---|---|
| ばかりに bakarini | Simply because | N2 |
| せい sei | Because of (negative) | N3 |
ばかりに bakarini
Simply because
Simply because; just because; simply on account of ~ | A conjunction indicating that a single factor causes a negative situation.
-
あの子は、体が弱いばかりにクラスメートにいじめられている。
That child is being bullied by his classmates simply because he is (physically) weak.
-
あの日たまたま休んでいたばかりに、大事な連絡を聞きそびれた。
I missed a really important announcement just because I happened to be absent that day.
せい sei
Because of (negative)
Because; due to | A dependent noun expressing a cause which brings about an undesirable result.
-
これは誰のせいでもない。
This is (due to) no one's fault.
-
今年は不況のせいで車があまり売れない。
Because of the depression, cars are not selling well this year.
ばかりに and せい are JLPT N3–N2 grammar points that Japanese learners often mix up. This page compares them side by side — meanings, usage and example sentences — so you can tell them apart.