Questions & Answers about Sen her gün koşuyorsun.
Why does the verb end in -sun?
The suffix -sun means 'you' (singular, informal). It matches the pronoun Sen. Because the present continuous suffix -yor always has an 'o', the 'you' suffix that follows it will always be -sun due to vowel harmony. You will never see -yorsin or -yorsun spelled with other vowels.
The translation says 'You run', but doesn't -uyor- mean 'are running'?
Yes! The Turkish present continuous tense (-iyor) is used for actions happening right now, but it is also widely used for habits and regular routines. Because the sentence includes her gün (every day), it translates best as the daily habit 'You run'.
Since the verb ends with -sun, do we really need the word Sen?
No, you don't. Turkish is a 'pro-drop' language, meaning you can often leave out pronouns like Sen because the verb ending -sun already tells us exactly who is running. Keeping Sen here just adds a little emphasis, like saying 'YOU run every day'.
Does the word her change based on vowel harmony?
No, her (every) is an independent word, not a suffix. It never changes its spelling, no matter what word comes after it. It just sits directly in front of the noun it describes, like in her gün (every day) or her sabah (every morning).