Well, thank you. When I don't know which word is right I usually look through the choices and "cynhaliad" is descripted as "aid" and that's the closest I could find. The words are more or less the same in other contexts too so I believed I couldn't miss with this one.
You might be right and I actually don't know why I thought the oposite way is the right one - if the word before a ends with vowel. Obviously, when explained things in one of lesson I didn't quite understand this part. I remember quite well there were some confusing sentences after explanation where first one or two seamed totally logical to me and I said them right in the gap of silence but one or two after that were confusing.
I was going with "ch" at first but then all of a sudden it just didn't seam right to me ... but yes, this might be the right one in deed.