I don't think that'll happen, Halla.

You don't necessarily have to be friends with someone to chat.  Once you've had an exchange of messages, you can carry on conversing. It just has to be you who initiates the exchange.

If you want to remove yourself from the search results go to "account settings" then click on "privacy" under friend requests you can untick the option to be there. 

Edit: You can also make it that only friends can send you messages in the privacy tab. There is a drop down.

@Halla

I understand your frustration. I keep actually getting messages from English speakers, that are not even learning a language I'm learning. You could try putting in your short intro, the one that displays on the search page what you are looking for and want and don't want. I've found not everybody reads the profile...they just click send message. It's a shame you can't choose that only people who speak the language you are learning can contact you.

Edited to add more.