A Keyphrase should be a short phrase that brings to mind and helps to remember the information on this frame.
だって(1)
after all, because
だって + Sentence
だって is used at the beginning of a sentence to provide a reason or an excuse. It is a colloquial conjunction often used in casual conversation, particularly when someone is defending their actions or explaining why something is the case.
Sentence-initial use
The word だって is placed at the very start of the sentence to introduce the reason for a previous statement or situation.
だって、眠いんだもん。
Because I'm sleepy.
だって、高かったんだ。
Because it was expensive.
だって、野菜が嫌いなんだ。
After all, I don't like vegetables.
Note
だって is very informal and is frequently used by children or in close relationships. It often carries a slightly defensive or explanatory tone, similar to saying 'But...' or 'After all...' in English. It is common to end the sentence with a particle like もん or もの to further emphasize the reason.