How would you explain that in English the progressive and perfect are necessary when,?

Question

in fact, from a logical point of view, they are wholly arbitrary?

Answer 1

Oh, I suppose they aren't so necessary when you are speaking to young children. However, at some point in time, children in elementary school all the way up to people in college who will be getting an English degree with an emphasis in grammar will need to know advanced grammar formation. Even the formation of the two sentences above require present progressive and future progressive forms. It may be only the names of those verbs which are arbitrary in nature.