¿Cuál es la diferencia entre emotional y affectionate y sentimental ?Puedes dar oraciones como ejemplo.

"emotional" is more broad, but "sentimental" and "affectionate" are more specific.

"emotional" can be used to describe intense expressions of emotion, of any kind.

For Example:
"Hey Katie, how was your weekend?"
"Great! I went to my cousin's wedding. I started crying during the ceremony."
"Really? Why were you crying? Did something bad happen at the wedding?
"No not at all! They were just so happy together, and I just started crying. I get a little emotional sometimes."

Here, Katie is not crying because she is sad, her intense feelings of happiness were so big, she started crying. A very emotional response.

With the word "affectionate" this is used to describe someone showing fondness. Usually not love, but a strong positive emotion instead.

For Example:
"Sadie gave her friend Michael an affectionate hug."
By using the word "affectionate", you can understand that Sadie may not love Michael romantically, but she feels very warm towards him.

"sentimental" is a word used to describe something that makes you recall positive memories.

For Example:
"Hey Josh! Look at all these photos of us from high school."
"Oh my god Ashley, we look so young, this must have been 15 years ago."
"Can you believe it has been 15 years since we were in high school? These photos make me feel pretty sentimental."

In this context, when Ashley says she feels sentimental, it means she's remembering fond memories from her past.