"I eat a sandwich."
Translation:Ik eet een boterham.
This is diffrent conjugation for the verb. There are rules for how any verb should be changed for each subject (Ik, Je, Ze (she), Hij, Het, Ze (they),We, Jullie and U). I'm not sure about all of them for the verb eten, but for Ik, Hij, Je and Ze (she) it's eet and for Ze (they), We and Jullie it's eten. You can find the rules in tips.