► 名詞
真剣さ [しんけんさ] meaning: serious rank: 3
☆ 彼は真剣さが足りない ⇨ He is lacking seriousness, is frivolous (☛ Seriousness in attitude)
► 形容動詞
真剣 [しんけん] meaning: serious rank: 1
☆ もっと真剣にやれよ ⇨ Do it more seriously. Be more serious (☛ Serious attitude. Literally means “with a real sword”)
☆ 私はその可能性を真剣に考えてみた ⇨ I thought about that possibility seriously (☛ Serious attitude. Literally means “with a real sword”)
真面目 [まじめ] meaning: serious rank: 1
☆ 少し真面目に考えたら？ ⇨ Why don’t you think a little seriously?
☆ 彼の話は真面目なのか冗談なのか分からない ⇨ I can’t tell what he said was serious or just a joke
☆ 真面目にやれ！ ⇨ Do it seriously! Stop fooling around!