English native speakers, how do you define Russian native speakers just by writing? I've met people on the internet who easily defined me as Russian, and I'm really curious.

Answer 1

Russians frequently omit articles from nouns. (“I bought book at store” rather than “I bought a book at the store.”) Other language groups do this as well, but I have found it most obvious among Russian speakers.

There are a few specific prepositions that get mixed up (like “in” and “to”).

Also, unusual use of reflexive verbs. Like, “I feel myself good today” instead of “I feel good today.”

Any of these sound familiar?

Answer 2

All I can tell you is that I recognize a Spanish speaker who is not fully fluent in English by their writing because of certain errors that correspond to Spanish grammar. For example, a Spanish speaker would say "I'm going" where we would say "I'm coming". The people who can tell you're Russian by your writing probably notice small errors or unusual ways of saying things that correspond to the way it would be said in Russian.