Can you put a male and female betta fish together?

Yes!!! if you want them to breed but make sure she doesnt mind if the male is nipping at her because she will kill him if she feels like she is being violated.Try putting a seperater between them until they seem like they know each other then take it out.If you don't trust those two being together while you're gone put the seperater back in there then take it back out, but keep a watchful eye out for those two.

No. If you want to breed them, only leave them together until they have mated, then immediatly remove the female. If you leave them together, one will kill the other. Don't leave them together!!I wouldn't recommend putting them together until he makes a bubble nest. If he does put the female in a plastic bag with water and seal it. Put it in the water. If the male flares up you are going to have to put a divider in or in separate tanks. The tanks should be about five gallons.
You can the female is ready to breed. If the female is looking larger than normal she could be ready to breed. You can start two different ways. The first way it to buy a net that separates the tank and see if they are interested in each other, If they are than you can put them together to breed. Another way is to put them both in the same tank without a divider and watch them both. The male should build a nest out of bubbles. If the female betta is interested than they are ready to breed and can be left in there until after they breed. If the female swims away than you should take her out to avoid the male killing her. After they have been bred you should not keep them together.