Yet is like "up till now", though it hints that the situation might be completed in the future.

My Russian isn't that good yet (yet is indicating that it's a work-in-process and that it's likely to get better)
I haven't seen the movie yet (yet is indicating that I'll probably watch it in the future)

I think все еще is the most similar

You can also use "still" in this context but it's mostly to negate expectations

My Russian still isn't that good yet ("I know you've expected my Russian to be better, but it's still not that good)
I still haven't seen the movie ("I know you'd thought I've already seen the movie by now, but I haven't").