penetrate vs dig into

penetrate and dig into both are verbs.

Word	Noun	Adjective	Verb	Adverb
penetrate	No	No	Yes	No
dig into	No	No	Yes	No

As verbs, dig into is a hyponym of penetrate; that is, dig into is a word with a more specific, narrower meaning than penetrate:

penetrate (verb)	dig into (verb)
come to understand	examine physically with or as if with a probe
become clear or enter one's consciousness or emotions
pass into or through, often by overcoming resistance
insert the penis into the vagina or anus of
spread or diffuse through
make one's way deeper into or through
enter a group or organization in order to spy on the members