Verbs cannot generally be modified by adjectives and nouns cannot generally be modified by adverbs. So, in "Running regularly is good for you", "running" is a verb because it is modified by "regularly", an adverb.
v ɜː b z WORD_BOUNDARY k æ n ɑ t WORD_BOUNDARY d̠ʒ ɛ n ə ɹ ɹ ə l i WORD_BOUNDARY b iː WORD_BOUNDARY m ɑ d ɪ f aɪ d WORD_BOUNDARY b aɪ WORD_BOUNDARY æ d̠ʒ ɪ k t ɪ v z WORD_BOUNDARY æ n d WORD_BOUNDARY n aʊ n z WORD_BOUNDARY k æ n ɑ t WORD_BOUNDARY d̠ʒ ɛ n ə ɹ ɹ ə l i WORD_BOUNDARY b iː WORD_BOUNDARY m ɑ d ɪ f aɪ d WORD_BOUNDARY b aɪ WORD_BOUNDARY æ d v ɜː b z WORD_BOUNDARY s oʊ WORD_BOUNDARY ɪ n WORD_BOUNDARY ɹ ʌ n ɪ ŋ WORD_BOUNDARY ɹ ɛ ɡ j ʊ l ə ɹ l i WORD_BOUNDARY ɪ z WORD_BOUNDARY ɡ ʊ d WORD_BOUNDARY f ɔ ɹ WORD_BOUNDARY j uː WORD_BOUNDARY ɹ ʌ n ɪ ŋ WORD_BOUNDARY ɪ z WORD_BOUNDARY ʌ WORD_BOUNDARY v ɜː b WORD_BOUNDARY b ɪ k ʌ z WORD_BOUNDARY ɪ t WORD_BOUNDARY ɪ z WORD_BOUNDARY m ɑ d ɪ f aɪ d WORD_BOUNDARY b aɪ WORD_BOUNDARY ɹ ɛ ɡ j ʊ l ə ɹ l i WORD_BOUNDARY ʌ n WORD_BOUNDARY æ d v ɜː b WORD_BOUNDARY