They can ask you a lot of things such as 'why' they do something a certain way such as 'why do you clean the conicle flask with only water?' or 'why do you rinse the burette with both water and the solution it will hold?' etc.
They can also ask you to calculate the concentration of acid/base (usually) of the analyte (they will probably ask you this).
They can give you a sample method and ask you where the error is.
They can ask you about how a method can be improved (validity, reliability and accuracy).
They can ask you to identify the equivalence point of a reaction (note: I used equivalence point, not end point).
There's a lot they can ask you on, you just need to understand all the ideas of titration, know the method in depth and be able to apply it to any situation.