Deparment of Linguistics
University policy is that a "full" TAship (50% time) should not take more than 20 hours per week, averaged out over the quarter. A "half" TAship (25% time) should not take more than 10 hours per week. If your TA work is taking more than this amount of time (and you are sure that this is systematic, and not a local perturbation), you should consider talking with the professor for the course and asking what might be done to bring your workload into line. In addition (or alternatively) you can let the Director of Graduate Studies know about it. In principle, he/she can do two things: (1) try tactfully to intervene with the faculty member in charge, and (2) intervene with the department Chair to try to get more TA's for the course. To the extent he/she takes any action at all, the DGS will always clear it with you first, since it's unlikely your complaint can be kept anonymous.