Can you marry your fiance if his wife refuses to give him a divorce?

no, your fiance has to be divorced first before he could marry another. if you forced to get married despite the divorce not granted, your marriage to your fiance is a void marriage -- not legal and existing from the start, and if you get pregnant and got kids, your kids will be illegitimated children because despite your marriage to your fiance but if he remains tied up with the first wife in the first marriage, in short, not divorced, then the first marriage subsist and remains valid.

No, he has to be divorced before he can get married again. But he can take her to court to get a divorce.

If you live in the United States, he can get a divorce even if she doesn't want to file. In many states it only takes a few months to a year to go through with or without the other spouses consent. In other states it might take longer depending.

A lot of it depends on how the spouse that won't let go decides to drag out paper work in the courts. One way or the other your man can get a divorce. He just has to file.