Although memorizing lines for an audition or performance is better done over a period of days or weeks, circumstances do not always allow for this. In the event that you must learn a monologue quickly, such as in one day's time, there are several tips and techniques you can use to make the task more manageable and the results more impressive. Repetition is key when learning lines, and even more so when the time frame is tight. Practice as much as possible in the time that you have and do not neglect the non-spoken parts of acting necessary in a monologue, such as your body language, facial expressions and use of pauses and silence.
Set aside solid chunks of time, such as several hours multiple times in the day, to practice. Work in breaks between sessions to allow time to relax and recuperate your mind to begin memorizing again.
Break the monologue script into sections, so you can “divide and conquer” the task and learn the lines in a less intimidating and overwhelming manner. Group the lines into logical sections and avoid breaking up a continuous thought.
Speak the lines out loud to yourself, using the same tenses, pronunciations and personality in saying them that you would in a performance or audition. Saying the lines out loud as opposed to simply reading them, helps your mouth practice forming the words and allows you to rehearse your breathing. Hearing the lines out loud also assists you in the memorization.
Seek out patterns or rhythms in the words, such as alliteration or rhyming words. This helps your mind to link the words together and aids your memorization.
Work in pauses and gestures into your monologue. This makes the talking appear more natural and less stiff. It also allows you to incorporate cues into your monologue that could be helpful to other actors in the scene or those working backstage, such as in the lighting.