The advantage of the "Sie" form when learning German

 Now, as you may know, when you learn a foreign language, that is probably the first time you come across the word "to conjugate". That means you have to change the form of the verb according to the subject that is placed in front of it. English is a nice language in that there are only a few occasions when the basic form of the verb, i.e. the infinitive, changes in any way. Mostly, it's a case of sticking a 's' onto the end of the verb with he, she or it. (As the Germans like to say: he, she, it - ein S muss mit.) Have has the form 'has' for the third person singular and it's only really the verb 'to be' that has three different forms (am, is, are).

German, however, has a different ending for each person. The verb for 'to go', gehen, is conjugated thus:

ich gehe            (I go)
du gehst            (you go - informal you, singular form)
er/sie/es geht    (he/she/it goes)

wir gehen        (we go)
ihr geht            (you go - informal you, plural form)
Sie gehen        (you go - formal you, plural and singular form)
sie gehen        (they go)

[When my Japanese friend realised there were three uses of "sie" (with and without a capital S) as the subject of a sentence, she gave up learning German, but that's just en passant.]

As you may have noticed, however, the form of the verb for the polite you form, Sie, is the same as the infinitive, which is why, when I first started to learn German formally at nearly the age of 14, I promptly addressed even family members using the "Sie" form, because then I didn't have to think about conjugating the verb. It gave them a jolt, I can tell you. "Don't call me "Sie"!" they'd exclaim. But it was so much easier for a learner of German.

Naturally, a language wouldn't be a language if there weren't any exceptions and there is one: it's the verb for 'to be' - sein.

It goes thus:

ich bin
du bist
er/sie/es ist

wir sind
ihr seid (now that's a difficult one to master)
Sie sind
sie sind

People always say that German is a difficult language, but when you compare it to Spanish and French, it's the only one of the three that has infinitives that is the same form as the polite you - which is fine, as it's going to take a while before a German allows you to call them by the informal you.