As adjectives the difference between sentimental and soft
is that
sentimental is characterized by sentiment, sentimentality or excess emotion while
soft is easily giving way under pressure.
As an interjection soft is
be quiet; hold; stop; not so fast.
As an adverb soft is
softly; without roughness or harshness; gently; quietly.
As a noun soft is
a soft or foolish person; an idiot.