Translation guide
The English verb "underestimate" can be expressed in Japanese through several verbs and phrases, depending on whether you mean misjudging a quantity, undervaluing a person or thing, or taking something too lightly. The most common and versatile word is 過小評価する, but in casual speech, 甘く見る or なめる are often used for people or situations.
Expressing that someone made an estimate or assessment that was too low, often leading to a mistake.
A formal, neutral verb meaning to underestimate or undervalue. Suitable for both concrete and abstract things.
彼の能力を過小評価していた。
I underestimated his ability.
そのプロジェクトの費用を過小評価してしまった。
We ended up underestimating the cost of the project.
To look down on someone's ability or worth; to underestimate a person. Often used when the person proves you wrong.
彼を見くびっていたよ。本当はすごい奴だ。
I underestimated him. He's actually amazing.
Literally 'to look sweetly', meaning to not take something seriously enough, to underestimate a challenge or opponent. Common in casual speech.
試験を甘く見てた。もっと勉強すればよかった。
I underestimated the exam. I should have studied more.
相手を甘く見ると痛い目にあうよ。
If you underestimate your opponent, you'll get hurt.
Very casual, often rude. Means to make light of someone or something, to not take seriously. Can imply contempt.
Can sound aggressive or confrontational. Use only in very informal situations.
あいつ、俺をなめてるのか？
Is that guy underestimating me?
Expressing that someone fails to recognize how good, important, or influential something is.
Again the standard formal term, works for value and importance as well.
この発明の重要性は過小評価されている。
The importance of this invention is underestimated.
To make light of, to disregard as unimportant. Often used for abstract things like risks, opinions, or warnings.
彼は健康を軽視している。
He underestimates the importance of his health.
その警告を軽視してはいけない。
You must not underestimate that warning.
To despise or look down on, often leading to underestimation. Slightly literary or formal.
Specifically about numerical estimates, like time, cost, or size.
Literally 'to estimate low'. Used for concrete numbers.
費用を少なく見積もりすぎた。
I underestimated the cost too much.
Also works for numerical underestimation, though slightly more formal.
必要な時間を過小評価していた。
I underestimated the time needed.
過小評価する is the safest, most neutral choice for any kind of underestimation. 甘く見る is common in everyday speech when you fail to take a challenge seriously. なめる is very casual and can be offensive; it implies looking down on someone with contempt.
彼の実力を過小評価していた。
I underestimated his true ability. (neutral)
テストを甘く見てた。
I didn't take the test seriously enough. (casual)
あの新人、なめてたらすごい成績出した。
That new guy, I underestimated him (looked down on him) and he got amazing results.
なめる is slang and can be very rude. Avoid using it with superiors or in formal situations. Stick to 過小評価する or 甘く見る unless you are with close friends.
相手を決して過小評価してはいけない。
Never underestimate your opponent.
敵を侮ってはいけない。
Don't underestimate the enemy.