sorrowing vs grieving

sorrowing and grieving both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sorrowing	No	Yes	No	No
grieving	No	Yes	No	No

As adjectives, sorrowing and grieving are synonyms defined as:

Other synonyms of sorrowing include bereaved, bereft, grief-stricken, mourning.

sorrowing (adjective)	grieving (adjective)
sorrowful through loss or deprivation	sorrowful through loss or deprivation