Smirk does not have a suffix. Usually words with only one syllable, don't have a suffix.
The prefix of the word "smirk" is "sm-" which means a slight curling of the lip, often indicating amusement or smugness.
The suffix word of "constitutional" is "tion," which forms the word "constitution."
The suffix is -ician...
-ary is the suffix.
The suffix in the word duties is -ies. This suffix just makes words plural.
The word smirk is a noun meaning sly smile. Synonyms for the word smirk include beam, grin, leer, simper, grimace, grim, sneer, visage, and smug look.
The prefix of the word "smirk" is "sm-" which means a slight curling of the lip, often indicating amusement or smugness.
Grin.
smirk
Josh had a smirk on his face when he got a B+ on his test.
Grin or smirk
smirk
smilestilestalestarestarksharkshirksmirk
perhaps "grimace"
"Johnny had a mischievous smirk upon his face after having read his sister's diary."
Smiling, beaming
The suffix word of "constitutional" is "tion," which forms the word "constitution."