"I drink water."
Translation:Ich trinke Wasser.
The verb endings change depending on the person. There are some remnants of this in English - "I drink", but "he drinks" with an additional "s".
You take a verb like "trinken" (to drink) and get rid of the "-en": "trink-". Then you add the ending depending on which person you're talking about:
ich trink-e (I drink)
du trink-st (you [informal, singular] drink)
er/sie/es trink-t (he/she/it drinks)
wir trink-en (we drink)
ihr trink-t (you [informal plural] drink)
sie/Sie trink-en (they/you [formal singular + plural] drink)