On hacker news, you respond to messages using the "reply" link below the comment rather than using twitter '@' style replies.

I am sorry, I missed the reply link. I will know from now on. Thanks!

The "Reply" link doesn't show up immediately. On deeper comments it takes longer to show up, thus discouraging the "flame exchange" problem.

Are you willing to put contact details in your profile? Or email me for more comments, suggestions and random advice?

As a quick example, the link grammar immediately highlighted that your second sentence:

  > I have been living in London for past 6 years
  > and my English still sucks.

doesn't parse. You need a "the" before "past" for natural sounding English. It really might help a lot, and perhaps get your error rate down to an acceptable level without having to pay for external assistance.

As a footnote, in the fourth sentence it did not pick up that you meant "conversation" and not "conversion."