Here you can discuss all things Ancient Greek. Use this board to ask questions about grammar, discuss learning strategies, get help with a difficult passage of Greek, and more.
for verbs, look for lists of "principal parts", which will basically give you all of the principal parts for irregular verbs. there is a good one at the back of Metzger's "lexical aids for students of new testament greek", which is a little book you should have anyway if you are learning koine. it lists all of the vocab of the new testament in order of frequency, down to words that are used 10 times or more--words that are used fewer than 10 times are not included. so you can start with the most frequent vocab and work your way down!
First say to yourself what you would be; then do what you need to do. ~Epictetus
yes, assume that nouns are regular unless your textbook says otherwise, since practically all of them are. It's the verbs that you have to watch out for.
The only odd nouns I can think of off the top of my head are ones that are the wrong gender for their declension (like οδος, which is feminine but second declension), but even those decline normally within their declension.
Which textbook are you using?
First say to yourself what you would be; then do what you need to do. ~Epictetus
