Exposure refers to the contact that the learner has with the language that they are trying to learn, either generally or with specific language points.
Extended speaking is a type of speaking activity that involves learners speaking for longer periods of time and in a freer form than controlled speaking practice.
Extrinsic motivation is a motivation to learn caused by external pressures such as work, because a parent has sent a learner to class, or the need to gain a qualification in the language.