In this episode of the All Ears English podcast, hosts Lindsay McMahon and Michelle Kaplan discuss the proper usage of the English modal verbs "could," "would," and "should." They explain that "should" is primarily used for giving advice or expressing possibility, "could" indicates past abilities or future possibilities, and "would" is used for making polite requests. The hosts provide real-life examples through role-playing scenarios to illustrate the correct usage of each modal verb in context, such as giving advice about finding an apartment, discussing past abilities, and making polite requests in a dinner party setting. They also promote a five-step lesson guide for listeners who want more in-depth help with these verbs.