No, not unless it was beginning the sentence. Capitalize, by the way.
Siblings? Capitalize the s? Use shift? Is that it? I don't understand your question.
Never.
South Carolina and South Dakota are U.S. states. They begin with the letter S.
The Last letter to U S is found in United States of America
Yes.
15
No the s in "secondary" does not need to be capitalized since Postsecondary is usually seen as one word.
phases
South Carolina South Dakota
I count twenty.
Socialization is a twelve letter word that begins with "s"
Only if you are referring to a proper noun (e.g., the United States).