Lexical Verbs
From TEFL World Wiki
Lexical Verbs are an open-class of verbs which are all verbs except auxiliary verbs. In other words, they tell of an action or state and can be added to with new verbs.
Lexical is used to show that the verb has a vocabulary meaning rather than just functioning as part of the grammar.
Simple tenses use only a lexical verb:
{subject} + {lexical verb}
I run.
I walked.
Continuous or Perfect tenses use an auxiliary verb and a lexical verb.
{subject} + {auxiliary verb } + {lexical verb}
I had run.
I was walking.
In other words, a lexical verb can sit on its own but an auxiliary verb requires a lexical verb so it makes sense:
* She will in the garden.
She will sit in the garden.
