Contracting 〜ているのだ to 〜てんだ
Grammar: Colloquial and Casual Speech
A verb ending in 〜て＋いる followed by the particle のだ may contract as てんだ.
First, the い in 〜て＋いる is dropped. Next, る becomes ん due to の following it. Finally, の becomes ん when followed by だ to です.
Examples
Why are you silent with 〜てんだ
Being the first to arrive at the clubhouse after school, Yui decides to change her hairstyle and see how long it takes the others to notice when they arrive.
Sacchan arrives next and starts up a conversation. Yui simply sits there without saying anything.
- さっちゃん:
- 「なんで黙ってんだ！」
- “Why are you being silent!”
Here, 黙っているのだ is contracted to 黙ってんだ.
You've been found out with 〜てんだ
Shin’ichi reveals that the murderer escaped out the window and onto the roof, naming the wheelchair-bound husband as the culprit. The husband points his cast-covered leg, but Shin-ichi knows better.
- 新一:
- 「もう、ネタはバレてんだ！！」
- “Your deceit has already been found out!”
- メイド:
- 「だ、だんな様、足が…」
- “Master, your leg...”