How to form a question in German

Move the verb to the front of the sentence Put the -st ending on the end of the verb e.g. Spielst du? If you're asking an older person or stranger, follow the same rules BUT use -en and Sie e.g. Spielen Sie Tennis? For a group use  -ihr and -t  e.g. Spielt ihr Tennis? BE CAREFUL of strong verbs in -du questions . The vowel will change . e.g. Siehst du fern?