Learn the lines accurately, but connect each line to what makes you say it. Memorization sounds mechanical when the actor is retrieving words instead of responding to the scene.
Read the whole page before drilling your dialogue. Know what the other person says, what changes in you, and what action your next line takes. Practise cues with a partner or recording, vary the pace, and begin from different places so the scene is not stored as one rigid rhythm. Then put the pages down and pursue what you want. If the other actor surprises you, let the line arrive through that new moment. The words stay the same. The path into them can remain alive. Accuracy gives you freedom when it is attached to thought, not when it becomes choreography.
Read the full lesson on reading the scene