说不出话 [- bu chū huà]lose one's tongue; cannot utter a word; could not have spoken for the world; His [Her] tongue failed him [her].; (nearly) robbed sb. of speech; Words failed him.:
•¶ 当我和失散已久的兄弟见面时， 我激动得说不出话。 Words failed me when I met my long-lost brothers.