In the following sentence which word is the adverb Marcia quickly ran up the steep steps?

The adverb is 'quickly'.

In the English language 99% of adverbs end in '---ly'.

Marcia quickly ran up the steel steps.

This sentence can be divided into three parts, ;- viz. subject, verb, object.

The subject is 'Marcia,

The verb is 'Ran'.

The object is 'steep steps.

Each Word is then of the following type. ;-

Marcia ; Proper Noun

Quickly ; adverb (qualifies the verb 'ran').

Ran; Verb ( past tense of the verb 'to run').

Up ; conjunction (joins two parts of a sentence)

The ; definite article

Steep ; Adjective (qualifies the noun 'steps'.

Steps ; Common noun. (plural of 'step').