sour grapesでいいのですが、負け惜しみを言うを英語でなんと言うのか？express sour grapesです。sour grapesには単数動詞が使われます。that's sour grapes.（負け惜しみでしょう）
ヘレナはクロアチア人ですが、彼女の英語はわかりやすい。もちろんBRIDGEの皆さんの目標はもっと上です。
http://www.youtube.com/watch?v=qPDCalVUtt8 1:23 sour grapes may have turned into stabbing tires. 負けた腹癒せはタイヤ刺しと化したようだ。
Caught on Tape: Politician Allegedly Slashes Opponent's Tires - Gary Smith Arrested
https://www.youtube.com/watch?v=CQ30dWFsBLY 1:38 maybe a case of sour grapes
Nigella Lawson Drug Accusations: Ex Assistants ClaimTV Chef Abused Drugs
https://www.youtube.com/watch?v=MpLLqkmyvDI 2:53 you're sour grapes
When Donald Trump Became ‘A Different Man' | MSNBC
https://www.youtube.com/watch?v=xXCOnoC4qQ8 2:30 any notes of sour grapes
Democrats Consider Giving Republicans Taste Of Their Own Medicine | Rachel Maddow | MSNBC
