how do i know if a betta is a female or a male?

Question
how can i identify if a betta is a female or a male? also can i breed a betta because when i bought my betta the guy in petland discounts told me that if i put two betta's together they will fight till death.

Answer
Hi Denisa;

Male bettas have long fins and females have short fins. The only time a male and a female can be put together is after they are both ready to actually spawn. The male needs a 5 or 10 gallon tank because he will be the one caring for the eggs and then the hatched babies. Once they spawn, you have to remove the female or he could kill her. The male builds what is called a "bubble nest". The female must have a round belly full of eggs. This happens after you have been feeding both male a female good wholesome protein foods like tubifex worms, chopped up earthworms, brine shrimp, etc. It can take several weeks, especially if the female is very young. Once she seems ready (round belly, white breeding tube extended from vent, vertical dark bars) you put them close to each other, but still in separate tanks. This "get to know each other period" encourages them both to be ready for breeding. Here is a great site about it with pictures too;

http://mermaiden.net/Betta/breeding_tips.php

Have fun!

At Your Service;
Chris Robbins