What part of speech is the word simply?

"Simply" can be either an adverb or an adjective, depending on its use in a sentence.

Here are some examples:

Adverb:

* "I simply don't understand." (modifies the verb "understand")

* "It's simply not true." (modifies the adjective "true")

Adjective:

* "The simple truth is, I'm lost." (describes the noun "truth")

* "It's a simple matter of time." (describes the noun "matter")

To determine the part of speech, consider how the word is being used in the sentence.