hi susan, its not as difficult as u think, u just need to read and realized the way the sentence is written and how it affects the noun, hope these help u!!
i started doing the grammar section first as its very easy for me finished 50 hrs online too but left the assignments to the end so need to finish them,havent done it for a while, anything else u need ill be happy to help :)
auxiliary verbs:
be (am,is, are)
have/has/had
do/does
For example
Peter
drives a car (drives is the main verb,theres not other verb in that sentence)
Peter
is driving a car (is, is the auxiliary verb,as is suports the main verb(driving) )
Does Peter drive a car? (Does is the aux verb,its supporting the main verb (drive) to form a question)
and its exactly like that with the auxiliary verb Have.