私は彼の言っていることがほとんど理解できなかった。と言いたいのですが、”ほとんど”はalmostを使うのですか？

I could hardly understnad what he was saying　と私なら言います。Almostは肯定的な意味合いの方が強いような気がします。 　

I was able to understand few he said. 　

If I were you,I would say ”I couldn’t really understand what he said”.
But I’m not sure if it’s correct... 　

I hardly understood what he was saying/what he said.
I could almost undertand what he said=もうすこしで解りそうだった。

　

I could not understand most of stuff he was saying, でいいんでないかい