The colloquial usages of だって

Beyond the simple quote usage of (だ)って there are two more. One of them is an extension of the quote one, but the other is historically unrelated.

The exclamatory だって appears in front of a sentence and is used like an adversative interjection similar to a casual しかし or as an explanation/logical continuation from the previous sentence.

「早く宿題しなさい！」
「だって、つかれてるんだもん」
“Hurry up and do your homework!”
“But I’m tired…”

だっておかしいじゃないですか。
I mean, don’t you find it weird?

The other だって is a more casual version of も/でも when used after nouns in the meaning of “even”.

そんなことは俺だって分かっている。
Even I understand that

This だって can also replace the ても conjugation of verbs and adjectives in the form of たって. It sounds very casual.

どんなものを食べたって問題ないな
No matter what kind of thing I eat, there’s no problem.

別に強くなくたっていい。
It’s okay even if you’re not strong.