When I am handwriting the names of books and plays, do I underline them or put them in quotes?

These are the works that I am writing:
Tortilla Flat, The Grapes of Wrath, The Pearl.

In handwriting, book titles will need to be underlined. Since all of these are books, underlining is what you need to do.

Titles of short stories and poems need to be in quotation marks. Titles of plays are usually treated like books -- underlined.

=)

Thank you for clearing that up for me; I wasn't sure.

10 years left unanswered, i suppose this is of no use to you

but this maybe perhaps use to others

you generally underline names of plays/books :)

You're welcome! I'm glad I could help. It can be confusing sometimes, but knowing the proper format for titles can make your writing more consistent and professional. If you ever have any more questions, feel free to ask!