What are the parts of speech in still waters run deep?

Let's break down the parts of speech in the phrase "still waters run deep":

* Still: Adjective (describes the waters)

* Waters: Noun (the subject of the sentence)

* Run: Verb (action performed by the waters)

* Deep: Adjective (describes the depth of the waters)

The phrase is a common proverb, often used to suggest that people who appear calm or quiet on the surface may have hidden depths or complex emotions.