"11 years old" in Engpsh is pronounced "eleven years old".
The number "11" in Engpsh is pronounced as "eleven". This is a basic Engpsh number, and its pronunciation has remained unchanged for centuries.
Examples in Engpsh:
She is eleven years old.
He will be eleven next month.
Examples in Chinese:
她已经11岁了。
下个月他就11岁了。