Compare the thoughts lady Macbeth expresses when alone to the thoughts she expresses to her husband

This depends on where you are in the play. L. Macbeth initially talks tough by herself and to her husband. She doubts her husband's ability the "catch the nearest way" and kill Duncan. By act 3 L. Macbeth is more lamenting her sorrows than in charge. She tries to maintain her tough talk with Macbeth, ("Are you a man"? ) but laments how everything has gone wrong when she is alone.

Act III scene II