～んだもん
〜nda mon
JLPT N3 Casual
Formation
Verb-casual + んだもん, い-Adjective + んだもん, な-Adjective + なんだもん, Noun + なんだもん
Used to convey a sense of justification; 'because', 'that's why', 'it's just that'.
When to use
Very casual, whiny/pouty justification; strongly associated with children or exaggerated pouting for effect.
Explanation
The ～んだもん grammar point is used when someone wants to give a reason, justification, or explanatory information in a more casual and emphatic way. It can be translated as 'because', 'that's why', or 'it's just that' in English. The formation differs depending on whether it is used with a verb, い-adjective, な-adjective, or noun.
Example sentences
遅れたんだもん、ごめん。
I was late, that's why I'm sorry.
Okureta nda mon, gomen.
-
It's delicious, that's why I want to eat more.
Oishii nda mon, mou chotto tabetai.
-
I'm tired, that's why I want to go to bed early.
Tsukarete iru nda mon, hayaku netai.
-
He's my friend, that's why I can't not help him.
Kare wa tomodachi nan da mon, tetsudawanai wake ni wa ikanai.
Causality (Because / Since / Due to)
- ～から、～〜kara、～N5Expresses reason or cause; 'because', 'since', 'so'.
- A。だから、～B。A. Dakara, ~B.N5Express reason or cause; 'because', 'so', 'therefore'.
- A。だって B。Datte~N2Used to give a reason, express cause or bring up a topic…
- ～からです〜kara desuN5Express the reason or cause; 'because', 'since', 'due to'.
- ～し、～し、～〜shi, 〜shi, 〜N4Express multiple reasons or characteristics; 'and'…
- ～ことから〜koto karaN2Indicates the reason or basis for something; 'because'…
- ～ものだから〜mono dakaraN2Express the reason or cause for something; 'because'…
- ～ので〜nodeN4Express a reason or a cause for something; 'because'…
- ～なぜなら〜nazenaraN3Express a reason or explanation; 'because', 'the reason is'.
- ～がゆえに～ga yue niN1Expresses the reason or cause; 'because', 'due to', 'as a…
- ～こととて〜koto toteN1Used to express the reason or premise for a decision or…
- ～がゆえの Noun〜ga yue no NounN1Expresses the reason or cause for something; 'because of'…
- ～おかげで〜okagedeN3Expresses gratitude or shows a positive result due to a…
- ～ばかりに〜bakari niN2Express an undesired situation or result caused by…
- ～せいで〜sei deN3Indicates that something or someone caused an unfortunate…
- ～あまり〜amariN2Expresses the result of doing something excessively or…
- ～とあって〜to atteN1Expresses a special situation or event due to certain…
Corpus examples (4)
「どうして運動会が嫌なの？」「だって、徒競走でドベになるのが嫌なんだもん」
"Why don't you like sports day?" "Because I hate getting last place in the foot race!"
今は、来月の海外旅行のことでもう頭がいっぱいよ。だって、久々なんだもん。
All I can think about is next month's vacation. I haven't been on one in so long.
-
Tom might have missed the train. He hasn't arrived yet.
彼女を避けようとしたけど、同じクラスだから難しかったんだもん。
I tried to avoid her, but it was hard, considering we were in the same class.