Do the research
I said it before, but I’ll say it again - learn the play and make sure you understand all the scenes, the characters, the themes, the settings...everything about it. Specifically, ask yourself some of these questions:
What is your character’s motivation; what are they trying to do?
How does your character fit into the scene; why is your character in the scene?
How does your character progress through the scene? For instance, does their mood and hence behaviour or speech change?
If you can answer these questions, then you’ll understand the subtext of your character’s words - what the character really means when they say them.
Doing this does several things for you:
When you’re learning the lines, it’s easier to memorise them if you understand the character and what’s driving them to say what they say. For instance, say you’re learning the part of a king who is madly jealous of his wife. As you learn the lines, you can think to yourself, "Well, I guess he’d say something like that, given he’s so jealous about his wife being with other men". Rather than learning just words on a page, you’ll be getting right into the character and learning the motivations and emotions that drive the dialogue.
If you know the character, then you can ad-lib more easily if you do forget your lines. The better you know the character, the more convincing and plausible your ad-libbing will be. You might even convince some people in the audience who know the play well!
Click here to move on to the next topic: Learn other characters lines