Even when memorized, a line can sound hollow. This confuses most novices. Memorization is comforting because it’s a quantifiable goal, but performance is an in-the-moment action, not a recitation. Help yourself by approaching every line as a response, even if you have no scene partner. Pause to feel what the last words said to you have affected you before saying your line. This micro-pause removes the sing-song quality of recitation and the fast tempo that comes from the memory being in charge.
One error we often make is that we attempt to fix a single “right” way of doing a scene in rehearsal and then do it that way each night. That results in a certain rigidity, since in real life we never speak exactly the same way twice. It is fine to vary tone, or tempo, or force, so long as the core intention of the action remains constant. One day in rehearsal we may do a scene more quietly and subtly, another day more fiercely and insistently. If the action’s purpose is consistent, these changes will result in nuance and subtlety rather than confusion and contradiction. The audience can feel when you are playing it in the moment rather than from a fixed model.
Even if you’re not with a partner, listening is what will keep your speeches alive. Decide what line your partner might say before each of your speeches — a challenge, a truth, a brush-off — and respond to it in your speech. If you’re having trouble keeping your focus, ask someone to make a recording of a neutral third party saying a line that you can respond to and pausing for your response. This will force you to react, rather than just going through the motions. Eventually, your body will come to expect the responses of another, which will keep the energy flowing outward instead of curling back on itself.
You can practice this daily. Take a minute or two to read the scene quietly to yourself, then get up and act the scene while pretending in each take that your partner is being supportive, then angry, then unaware of what you are saying. Observe that your words and actions shift naturally without forcing. After two or three takes, select the take that you feel most truthfully acted and do one more take. This time, try to think through your words and actions instead of merely trying to express the emotion. Finally, I recommend taping that last take and checking to see if your reactions appeared to be appropriately thought through or more choreographed.
If you get stuck and everything sounds the same, try deliberately altering something about your delivery (faster than usual, more space between the words, whatever) and you might be surprised at what other emotions and variations you start to find in the text. You don’t have to do the scene differently for different’s sake, you just need to remind yourself with a trigger that this is an unfolding series of moments, not something to be merely delivered. If memorization is a tool that serves spontaneity rather than an excuse for its absence, you can really start to taste the words.