This unit introduces the concepts of tense and aspect. First, we will make sure that you are able to identify all the "tenses" (as they are sometimes - not wholly accurately, as we will see - referred to). Next we will look at the meaning of the concept of tense. And finally we will examine the meaning of aspect.
The continuation of the text ('Dad gets a wave and a nod': how we greet now) runs through the the first two quizzes.