Normally no. They may be if the child has a mental disability.
In California, parents are legally responsible for their children until they reach the age of 18.
Yes.
No, the child is 18 therefor an adult in charge of their own actions.
Parents in Indiana are legally responsible for their children until they reach the age of 18.
No they are not.
Legally responsible in what context? Parents are responsible for providing their children with food, shelter and adequate supervision. However, if the minor gets into legal trouble, the parents aren't necessarily vicariously responsible.
Children are not legally responsible for their parents, so I can't imagine how you would owe money to them.
In Tennessee, parents are generally not legally responsible for their children who are over the age of 18. Once a child reaches the age of majority, they are considered adults and are responsible for their own actions and decisions.
If parents are aware that their teenage children are using illegal drugs and they allow this to happen, then they do have some legal responsibility. If it is happening without their knowledge, then they are not legally responsible.
In California, a minor (under 18) who leaves home without parental consent may be considered a runaway. Parents can file a runaway report with law enforcement, who will try to locate the minor and return them home. Parents are legally responsible for their minor children and can face consequences if they fail to provide care and support.
Because you're not married, he isn't legally responsible for you. Of course, he is legally responsible for any children for whom you and he are the parents.
Whether it's your parents or mine, you won't have to pay (other than through taxes) - children are not legally responsible for their parents.