だもん

A contraction of だもの, which itself is だ (copula) + もの (because, the thing is). The ん ending softens the expression and gives it a childish or intimate quality.

Usage

Most commonly used by women and children, or in deliberately cute or casual speech. Men may use it in very informal settings or for humorous effect. Often preceded by だって (but, because) to form the combination だって...だもん (but... because...). The tone is typically one of making excuses or insisting on a point.

Register

Very informal. Not appropriate in formal, business, or polite contexts.

Similar words

• だもの — because (slightly more mature than だもん; same meaning)
• だから — because, so (neutral; standard causal connector)
• んだもん — because (variant with explanatory ん; same usage)
• もん — because (even more casual abbreviation; childish)