N5 — outside your level filter
Is said whole, with nothing composed onto it and takes no だ／です, so there are no forms to conjugate.
結構です
kekkoudesuthat's fine, thank you (declining politely)N5expression
Example sentences2
コーヒーのお代わりはもう結構です。
koohii no okawari wa mou kekkou desu.
I'm fine without a coffee refill, thank you. neutral
お気遣いなく、これで結構です。
okizukai naku, kore de kekkou desu.
Please don't trouble yourself, this is fine as it is. formal