Noun + 很 + 深
The adjective 深 (shēn) means "deep" and can describe physical depth or abstract intensity. When used with 印象, it expresses that an impression is strong or profound, as in 印象很深 (a deep impression).
这条河水很深,小心一点。
zhè tiáo hé shuǐ hěn shēn, xiǎoxīn yìdiǎn.
The water in this river is very deep, be careful.
我对那次旅行的印象很深。
wǒ duì nà cì lǚxíng de yìnxiàng hěn shēn.
I have a deep impression of that trip.
夜已经很深了,你早点休息吧。
yè yǐjīng hěn shēn le, nǐ zǎodiǎn xiūxi ba.
It's already very late at night, get some rest early.