Grammarian
As Grammarian, you listen for proper use of language. You may choose to concentrate on one particular aspect of language and report on usages pertaining to that aspect. For example, you could listen for double negatives or redundancies. It is the choice of the Grammarian what tack to take during the meeting but you should inform the members, if possible, of this at the start of the meeting.
The Grammarian is in charge of the Word of the Day. Find an uncommon word (something that is under used or even misused) and challenge the club to use it properly in their speaking roles. Keep track of those who uses it properly. During your report at the end of the meeting is when you anounce who the "winner" is