Explain how to form the usted form of the imperative of the regular -ar verb hablar.

To form the usted form of the imperative of the regular -ar verb hablar, you simply need to drop the -ar ending of the infinitive form and add the appropriate ending.

For the verb hablar, the usted form of the imperative is formed by dropping the -ar ending to get the stem "habl-" and then adding the ending "-e" for regular -ar verbs.

So, the usted form of the imperative of hablar is "hable."