Answer :
Final answer:
The informal English phrase in the excerpt is 'when I was growing up.'
Explanation:
Informal English phrase: 'when I was growing up.'
In the excerpt from Amy Tan's essay 'Mother Tongue,' the phrase 'when I was growing up' is an example of informal English as it is commonly used in casual conversation rather than formal writing.
Learn more about informal English usage here:
https://brainly.com/question/3554765