The forms of the simple present and past tenses, the imperative and non-finite forms (i.e. the participles and the infinitive) make up the basic conjugation of the German verb. They are all single words, formed by adding different prefixes or suffixes to the verb root, or by changing the form of the root, especially by altering the vowel. [hammer2017german]
In German there is no difference between singular and plural in the polite form, you always talk in plural.
[ ] understand section 14.1.2 in [hammer2017german]