Yes, and sometimes younger depending on which state/country you are in as laws change everywhere.
Eighteen.
Not legally. Each partner must be over eighteen.
He was eighteen.
Not before you are eighteen.
Shakespeare was eighteen when he married Anne Hathaway, eight years his senior.
Don't do it.
Your parents' consent.
Yes, because eighteen is considered the legal age of consent.
Yes. They married when he was eighteen he married Anne Hathaway, who was eight years older than he was, and it was her who was included in his final will.
You have to be sixteen to get married, seventeen to drive and eighteen to vote and drink alcohol.
1805 because eighteen years before, Davy Crockett was born
No but you can