cái gì

cái (“something”) +‎ gì (“what; whatever”).

• (Hà Nội) IPA^(key): [kaːj˧˦ zi˨˩]
• (Huế) IPA^(key): [kaːj˨˩˦ jɪj˦˩]
• (Saigon) IPA^(key): [kaːj˦˥ jɪj˨˩]

• Audio (Saigon):

  (file)

cái gì

1. something

   ai, cái gì, con gì ― the who, the what thing, the what animal

Cái gì is an example of using the pronoun gì with a classifier, cái being the most generic classifier, which can be used for emphasis. Other combinations including con gì and quả gì.

cái gì

1. what?
2. what the heck!

cái gì

1. Used to express that a word should not have been said.

   Anh cái gì mà anh.

   (please add an English translation of this usage example)

   Anh anh cái gì?

   (please add an English translation of this usage example)