No, only when it is used as part of the proper noun.
Examples:
I want to see Mother Theresa in person.
My mother cooks dinner everyday.
no
You mean if you are writing out the number like "thirty-five"? No. You don't capitalize it in the middle of the sentence.
it depends on where you place dolphin in a sentence. If it is the first word of a sentence, then yes, it should be capitalized. If it is in the middle of a sentence, then it does not need to be capitalized.
no
No.
No you don't.
No.
No.
In the middle of a sentence, you don't capitalize second floor.
Yea
No you don't.
No it shouldn't be capitalized.