1、生日快樂的英文為:happy birthday,讀音:英[ˈhæpi ˈbɜːθdeɪ],美[ˈhæpi ˈbɜːrθdeɪ]。
2、[例句]The cake had Happy Birthday piped on it.蛋糕上裱了“生日快樂”的字樣。