Final answer:
In the play 'Trifles', Alfred does not warn Major, Hollis, and James about the alarm system at Epsteins.
Step-by-step explanation:
In the play 'Trifles' by Susan Glaspell, Alfred does not warn Major, Hollis, and James about the alarm system at Epsteins. This is because Alfred is a minor character and is not aware of the alarm system or its significance. His role in the play is to provide comic relief and is not involved in the investigation of the crime.