1.
impossible, unreasonable
Beyond what is possible or reasonable.
それは無理だ。
That's impossible.
無理は言わないで。
Don't make unreasonable demands.
今日中に終わらせるのは無理です。
It's impossible to finish it today.
その計画は予算の面で無理があると思います。
I think that plan has problems budget-wise.
一人でやるのは無理だから、手伝ってくれる？
It's impossible to do it alone, so could you help me?
2.
forcing, overdoing
Doing something beyond one's capacity.
無理しないでください。
Please don't overdo it.
無理して食べなくていいよ。
You don't have to force yourself to eat.
体調が悪いときは無理をしないで休んでください。
When you're not feeling well, don't push yourself and please rest.
若いころは無理がきいたが、年を取ると回復に時間がかかる。
When I was young I could push myself, but as I get older it takes time to recover.
締め切りに間に合わせるために無理をして徹夜した結果、体調を崩してしまった。
As a result of pushing myself and staying up all night to meet the deadline, I got sick.
無理 expresses impossibility, unreasonableness, or overexertion.
GRAMMATICAL FUNCTIONS:
- Noun: 無理だ (it's impossible)
- Na-adjective: 無理な要求 (unreasonable demand)
- Verbal: 無理する (to push oneself too hard)
COMMON PATTERNS:
- 無理しないで: don't overdo it
- 無理を言う: to make unreasonable demands
- 無理がある: there are problems, it's unreasonable
- 無理もない: it's understandable
COMPOUNDS:
- 無理矢理: forcibly, by force
- 無理難題: unreasonable demand
CONTRAST:
- 無理: impossible, forced ↔ 可能: possible
- 無理: unreasonable ↔ 当然: natural, reasonable
NOTE:
無理しないでね is a common expression of concern meaning "don't push yourself."