Usages of давно
Я давно мечтаю стать популярным блогером, но пока пишу только для друзей.
I have long dreamed of becoming a popular blogger, but for now I write only for friends.
Я давно читаю книгу.
I have been reading a book for a long time.
Elon.io is an online learning platform
We have an entire course teaching Russian grammar and vocabulary.