This may be a very silly question but it is one I have been thinking about a lot recently.
My two main characters in my historical novel are two guys and I worry that they have very similar characters; yet I am struggling to make them different because somehow they just fall back to being how they were. 
How can I work on their characters to make them very different?
When you are developing characters how do you differ their speech and manners and not fall into making them very similar?
I need them to rub off on each other and fit like a good pair, they are my main detectives in the story and I don't want people to become easily bored with them.
I'm finding it very easy with the female characters to make them different I seem to be struggling more with my male characters.
Thank you and I hope it is ok for me to post this as it is for my novel that is not fantasy, but it is about character development and I could also struggle with this in my fantasy stories. 
