When giving directions in German in a formal setting, one has to put the word 'Sie' after the verb, as such:
gehen Sie zwanzig Minuten geradeaus
How could I say the same sentence in an informal setting (using gehst and du)?
German Language Stack Exchange is a bilingual question and answer site for speakers of all levels who want to share and increase their knowledge of the German language. It's 100% free, no registration required.Sign up to join this community
Gehen Sie zwanzig Minuten geradeaus is an example of an imperative.
There are three main forms for the imperative in German, formal, informal singular and informal plural.
Technically, the formal imperative is a separate verb conjugation, but it's nearly always identical to the infinitive and I think that's the source of confusion here. In the case of sein, the formal imperative is different, seien instead of sein: Seien Sie vorsichtig. The informal singular imperative is more complex, but it's usually just the verb stem with an optional -e at the end. (The -e is sometimes mandatory depending on the verb.)
Also, while the subject must be included in the formal imperative, it's usually dropped in the informal version. So either Geh zwanzig Minuten geradeaus or Gehe zwanzig Minuten geradeaus would work. If you're talking to more than one person in an informal situation, then you need to use the informal plural imperative. Again, this is technically a separate verb conjugation but in this case it's identical to the present tense for ihr. So Geht zwanzig Minuten geradeaus would be the usual way to say it.
There are (at least) three other imperative forms in German, but they aren't relevant for giving directions. Also, I omitted some of the details on forming the imperative here, so you should refer to a grammar for more complete information; most have either a separate section or chapter on imperatives.