Please correct the grammatical flaws in the given sentence
I used to consider Russian one of the hardest languages to learn and here are some foreigners who not just write in good Russian, but also manage to make jokes, keep to a certain style and even write poems.
I used to consider Russian one of the hardest languages to learn, and here are some foreigners who not only write well in Russian but also manage to make jokes, keep to a certain style and even write poems.