It depends what you mean. 'I see my brother shaves' can make sense, but means something different to 'I see my brother shave' or 'I see my brother shaving'. For example, if you had not seen your teenage brother for a while you might see evidence that he has started shaving and say 'I see my brother shaves!' meaning 'It is obvious to me that my brother shaves', not 'I see him engaged in the act of shaving'