Verbal Parts

Hello,

I'm a Czech student, who unfortunately has to study English Syntax for one semester (oh man, it's so hard!). We got this homework and I'm not sure if I really understand the task:

1, (i) Underline the Verbs/ Verbal parts of the main clause Predicates

(ii) How many elements does eth 'Verbal part' of each predicate
have?

(iii)Which part of the complex tends to carry grammatical categories of the Verb
(Tense/Aspect, Agreement) and which is the locus of 'lexical meaning'? Answer this in
terms of right/ left side and w.r.t. the categorial status of the relevant element.

(a) Mary also (reads exciting novels)vp.
(b) Johanna might (run away with the sailor)vp.
(c) Mr. Todd had been (shaving the customers with real enthusiasm)vp.
(d) My parents are not (looking forward to his arrival).
(e) Some people (take showers twice a day)vp.

(f) Jane was allowed to (look at those pictures)vp.

I guess I know the Verb phrases or Predicates (I put them in the brackets and wrote "vp" next to them).

The Verbal parts are: reads, run, shaving, looking, take, look

Then in (ii) - how many elements does it have - am I supposed to count the words or the whole phrases? Or what elements in Verbal parts? If the Verbal part is "run", then there's only one element, isn't it?

And then in (iii) - I thought I undestood the question. The auxilary verbs and some suffixes (etc.) tends to carry the grammatical categories. But that last part confuses me - in terms of right/left side? What does that mean?

Also I would like to ask one more question: Why are Verbs central for sentence structure?

I know it's a really long question and I'm sorry for that. Our teacher uses so many different terms for one event in his script that I don't know what is what.