Question

In this sentence " A lion was stalking an antelope in the high grass." Is stalking a

Verb phrase, main verb, linking verb, helping verb, direct object, indirect object, predicate noun, predicate adjective

( Whoever answers get 53 points)

Answer 1

it is the main verb.  Since stalking is the action of the lion it is the main verb.

Answer 2

Main Verb.

"was" is your helping verb.
"Grass" is your direct object.
"Lion" is your noun.