N2 — 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.
頭が固い
atamagakataito be inflexible in one's thinkingN2expression
Example sentences2
祖父は頭が固いので、新しい考えを受け入れません。
sofu wa atama ga katai node, atarashii kangae o ukeiremasen.
Because my grandfather is inflexible, he won't accept new ideas. neutral
そんなに頭が固いと、みんな困るよ。
sonna ni atama ga katai to, minna komaru yo.
If you're that inflexible, everyone will have trouble. casual