Trink/trinkst; Is this a matter of feminine/masculine/neuter?
Only nouns have gender, german verbs have a stem and an ending, the ending changes depending if you're using ich/du/sie/er/Sie/wir/ihr ... So for your example it would be Ich trinke, Du trinkst, sie trinkt, Sie trinken, etc.
@phea It's a matter of person. Ich (I) is first person; Du (singular you) is second person; Sie, Er, Es (She, He, It) is third person. So trinke is first, trinkst is second and trinkt is third.
Maybe this will help remembering: if you read books in archaic English, such as old Bible translations, you may have noticed that there are sentences such as "thou drinkest". In today's English it's "you drink", but notice how similar "thou drinkest" is to "du trinkst".
Yes, it changes based on person: ich trinke, du trinkst, er,sie,es trinkt, Sie trinken, wir trinken, ihr trinkt, sie trinken. Another difference is verb stems ending in d, t, or a consonant cluster and verb stems ending in s, z, or ß are conjugated differently. http://gerxmanxney.tumblr.com/page/2