soft-soap vs sweet-talk

soft-soap and sweet-talk both are verbs.

Word	Noun	Adjective	Verb	Adverb
soft-soap	No	No	Yes	No
sweet-talk	No	No	Yes	No

As verbs, sweet-talk is a hypernym of soft-soap; that is, sweet-talk is a word with a broader meaning than soft-soap:

Other hypernyms of soft-soap include blarney, cajole, coax, inveigle, palaver, wheedle.

soft-soap (verb)	sweet-talk (verb)
use flattering talk on somebody	influence or urge by gentle urging, caressing, or flattering
persuade someone through flattery