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.
Grin.
smirk
The prefix of the word "smirk" is "sm-" which means a slight curling of the lip, often indicating amusement or smugness.
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."