It’s because Spanish sentence structure is different from English. In Spanish the sentences “Can I tell you? (¿Te lo puedo decir?) and “I can tell you.” (Te lo puedo decir.) are formed the same way. The initial punctuation lets the reader know that the sentence is a question or exclamation or not so they can parse the sentence properly from the start.

English manages the exact same thing without the leading punctuation.

English changes the syntax of the sentence. Spanish uses punctuation marks. It’s just differences in languages. Personally I appreciate them since it helps me read Spanish quicker with fewer parsing errors.

"How would I find out?"

I can tell you.

I can tell you?

Yes, English uses word order to define grammar in many more sentences than Spanish, but not exclusively.