@peterkotrcka
I feel you mate! Been learning greek on and off for some time now, it is very hard for me. Memorizing words is super δύσκολο, and whatever I manage to stuff in my brain evaporates after 2 weeks if I don't come back to it. Speaking is whole another thing - it doesn't progress at all regardless of how much you read and memorize stuff, only practice here.

Another curious thing I've had is that after 300+ days perfect strike on duolingo I took a break of 1 week and could only remember 3 words afterwards. So in my humble opinion that app is not worth spending time on it, best thing so far was just learning the rules and independently trying to learn as many words as possible.