By now you should have settled on a theme for your Hamlet essay either through consultation with your professor or perhaps through a Reference or Book source.
The articles found in databases are much more specific in nature than the content of the book sources you have examined. Therefore, it will help you to select keywords that reflect the theme of your essay.
For example, I am writing about the theme "mortality in Hamlet," specifically in the "Alas, poor Yorick" speech. What key terms can I take to the library databases?
Hamlet and mortality
Hamlet and momento mori
"alas, poor Yorick"
Hamlet graveyard soliloquy
The connector AND will tell the database to find both words. You do not have to type it. The term OR will tell the database to find either one word or the other types word, expanding your search results. NOT excludes a term from the search results.
ex, Hamlet AND mortality OR death; Hamlet and Yorick OR gravedigger