you
In German, the word 'du' is used to address someone informally, similar to 'you' in English. It is used in situations where a close or familiar relationship exists between the speaker and the person being addressed, such as with friends, family members, or children. The formal way to say 'you' in German is 'Sie'.
You are beautiful
In this sentence, 'Du' is used as a subject pronoun to indicate you. 'bist' is a form of the verb 'sein' which means 'to be', and it is used when talking directly to someone informally. 'schön' translates to 'beautiful'. So, 'Du bist schön' means 'You are beautiful'.
How are you, you?
This is a greeting phrase often used among friends in informal communication in German-speaking countries. 'Wie geht es dir?' means 'How are you?', and 'du' also means 'you' in English, it's used here for emphasis or to show a friendly tone.
What are you doing
The sentence 'Was machst du' is a question, where 'Was' translates to 'What', 'machst' is a conjugated form of the verb 'machen', meaning 'to do', and 'du' is the pronoun for 'you'. This sentence can be used in a variety of contexts such as to ask someone about their current activity or plans.