Here's why:
* were is the helping verb (auxiliary verb) that indicates past continuous tense.
* running is the main verb, describing the action.
Together, they form the verb phrase that tells us what the children were doing.
Here's why:
* were is the helping verb (auxiliary verb) that indicates past continuous tense.
* running is the main verb, describing the action.
Together, they form the verb phrase that tells us what the children were doing.