Rooster or not?

[Rexhame rooster]

Hi folks , we are new to the chicken world and my buddy told me to come here with my question . We have 12 chickens which two of them are leghorns and we have always suspected since chick stage that one of them was a rooster , it's crown was much bigger than the other one and it did the rooster crow for a while now, he also was very aggressive towards the other chickens , so we found him a new home , now the other one has never made a peep before and was not really aggressive at all bit now that Larry , the first one is gone two days now , the other one is starting to crow , is this just a hen trying to take on her buddies role or do I have to get rid of another rooster?? How can I be sure if it's a rooster or not , what else should I look for ? Thanks Rexhame rooster

 

[PoultryGirly]

A picture would help.
Big wattles and a big comb will usually determine a rooster.

 

[Fred's Hens]

A photo would help a lot. The leghorn has a pronounced comb, so that in itself may make them a bit hard to sex. However, the subordinate cockerel wouldn't likely crow, as that was left to the other alpha male. Now, if this is a cockerel, he made indeed be Big Man in Charge and now start to crow. Pullets who attempt a crow don't do it very well.

Again, a photo is the best way for the forum to give you better guidance.