由来・語源
16世紀起源のことわざ。旧形は「you can't eat your cake and have it」で、ケーキを食べれば手元に残らないという比喩に基づく。
イディオム
can’t have your cake and eat it too
choicesvery_commonintermediate
用例
You can’t have your cake and eat it too — if you quit your job to travel, you can’t expect the same salary.
仕事を辞めて旅行したければ同じ給料は期待できないよ。両方は無理だよ。
She wanted the promotion and more free time; I told her she couldn't have her cake and eat it too.
彼女は昇進も自由な時間も欲しがった。両方は手に入らないよと伝えた。
Politicians often promise conflicting things; voters should remember you can't have your cake and eat it too.
政治家は矛盾する公約をしがちだ。有権者は両方は無理だと覚えておくべきだ。
If we cut the budget, we’ll save money but services will suffer — you can't have your cake and eat it too.
予算を削ればお金は節約できるがサービスは低下する — 両方は無理だ。
He wanted to spend all his savings on a trip and still buy a house next year — you can't have your cake and eat it too.
彼は貯金を全部旅行に使って、来年家も買いたがっていた。両方は無理だよ。
補足（日本語）
口語的でやや説教的。選択やトレードオフを指摘する場面で使う。普通は否定形で用いる。フォーマルにも可。
補足（英語）
Neutral to informal, often reproachful; used to point out a necessary choice or trade-off. Usually appears in the negative form; usable in both casual and formal contexts.
文法・使い方の注意点（日本語）
定型表現。通常は否定形で用いる（can't/you can't）。語順は概ね固定。類義表現に "have it both ways" がある。
文法・使い方の注意点（英語）
Fixed idiom; commonly appears as "can't have your cake and eat it too" or as the variant "you can't have it both ways." Usually negative; word order is generally fixed though older texts reverse the clauses.
補足（日本語）
口語的でやや説教的。選択やトレードオフを指摘する場面で使う。普通は否定形で用いる。フォーマルにも可。
補足（英語）
Neutral to informal, often reproachful; used to point out a necessary choice or trade-off. Usually appears in the negative form; usable in both casual and formal contexts.
類義語・近い表現
反義語
make a sacrifice, accept a trade-off