Anyone who has a great grandparent in common will be second cousins.
Another way to look at this is to note that the grandchildren of your great aunts and great uncles are your second cousins. Their children are your second cousins, once removed, and their parents are your first cousins once removed.
Some of your second cousin's cousins could be your cousins, and some would not be. It depends on whether or not your cousin's cousins are on your side of the family or not.
Most people have both maternal and paternal cousins. If you are cousins with this person on their maternal side, then all cousins related to him through his mother would be your cousin too. However this person's paternal cousins through his father would have no blood relation relation to you.
Not necessarily. First cousins have grandparents in common, where second cousins have great-grandparents in common. Your cousin will have cousins who are also your cousins (first, second, removed of various degrees, etc) but will also have cousin who are not related to you.
Another way to think of it is that first cousins are the children of siblings while second cousins are grandchildren of siblings.
Your parent's children are first cousins of the children of their brothers and sisters. Your grandparent's grandchildren are second cousins to the grandchildren of their brothers and sisters.
It is possible. The key is if you share a common ancestor. If you don't, there is no relationship.
If you are his second cousin, he is your second cousin
Asking about your second cousin's cousin's cousin is asking about a complex but poorly defined relationship. Are the cousins of the second cousin his first cousin, second cousin, fifth cousin twice removed, or something else. It is likely that a cousin's cousin's cousin is not related to you at all. It is also possible that your second cousin's first cousin's first cousin is also your second cousin.
Your second cousin's niece is the daughter of your second cousin's brother or sister. Your second cousin's brother or sister is also your second cousin, so this question is the same as "How are you related to the daughter of your second cousin."The daughter of your second cousin is your second cousin, once removed.
Your first cousin's second cousin may be your second cousin as well, or may not be related to you at all.
Your child is your cousin's second cousin. (And he/she is your child's second cousin)
Your second cousin is your parent's cousin's child. You and your second cousin share a great-grandparent (not a grandparent).
He is your second cousin also
No, your father's first cousin is the parent of your second cousin. Your second cousin is your father's first cousin, once removed.
The child of your second cousin is your second cousin, once removed.
Your mother's second cousin is your second cousin, once removed.
Your second cousin's daughter is your second cousin, once removed.
Your second cousin's child is your second cousin, once removed.