There are a lot of reasons why couples file for divorce.
But not all divorces filed are granted by the court.
Like other laws, there should be valid grounds before divorces can be filed and granted.
In order to shed light on the subject, here are some common questions about divorce grounds:

1. Can we change the grounds that I originally filed for divorce?Yes, as long as it's valid.
   That's all the court cares about.
   If it's valid and will help you in your cause, then it's alright to do so.
   It can be a case-to-case basis, though.
   
2. Is separation a valid ground for divorce?It is, but it may vary according to the laws of the state that you're in.
   It is best to consult a lawyer regarding the matter.
   There are some states that accept separation as legal grounds for divorce.
   
3. What exactly constitutes abandonment?Basically, if the person leaves and doesn't come back.
   There are some cases when a couple fights, one leaves the house and stays over at a friend's house and then returns.
   This can't be considered abandonment, even if said couple doesn't talk to each other or the person returns at the house when the spouse leaves for work.
   
4. Can the husband's abusive behavior become a valid reason for divorce?Yes.
   Abuse is one of the common grounds for divorce.
   You have to consult with your lawyer regarding what grounds apply to you, since it varies from state to state.
   But it's certainly valid.