Grammar: Groups & phrases: Verb group: Structure of the verb group

Overview

Function and structure of the verb group: Form and function

Here is a summary of the different elements or forms in the verb group and the different functions they perform: 

Form	Function
auxiliaries have and be	Finite in the verb group, expressing 'aspect' .	Dotty has done her homework, Kitty is going to the cinema.
auxiliary be	Finite in the verb group, expressing 'passive voice' .	Dotty was given a book for her birthday (passive voice).
auxiliary do	Finite in the verb group, as 'helper' verb in an interrogative structure and in a negative clause.	Did Kitty come home late from school? Don't (do not) come home late from school, Kitty!
	Finite in the verb group, expressing emphasis.	Kitty did come home late from school.
modal auxiliaries can, may, must etc	Finite in the verb group, expressing 'modality' , ie probability, obligation, inclination etc.	You must do your homework, Bozo!
main (or lexical) verb	Event in the verb group; expresses through lexical or content verbs what is happening in the clause. The main verb functions as Finite and Event when there is no auxiliary present in the verb group.	The children have been chasing the ghost around the kitchen. The ghost slipped into the bottle.

Note that the terms Finite and Event are written with a capital letter to remind us that they are functional terms.