Thank you. Can you please clarify this doubt to me?
If the answer is "since 1998" can the question be: How long is it since you got married"?
Is the sentence "How long ago did you marry"? wrong. The verb is "get married".
When did you divorce your fist wife?
"How long have you been married?" <~~Yes, that's the best way to phrase the question.
The answers then could be any of these:
Since 1998.
Thirteen years.
A long time!
etc.
Yes, the answer "since 1998" can be a response to the question "How long is it since you got married?" The phrase "since 1998" indicates the time period that has passed since the marriage took place.
Regarding the sentence "How long ago did you marry?" it is not grammatically incorrect, but it does sound a bit awkward. Generally, when asking about the time since an event occurred, it is more common to use the verb "get married" instead of just "marry." Therefore, a more natural way to phrase the question would be "How long ago did you get married?"
Lastly, the sentence "When did you divorce your first wife?" is grammatically correct. It is a direct question asking for the specific time of the person's first divorce.