His son is enough age to understand that.

I know 'His son is old enough to understand that' is correct.
Does 'His son is enough age to understand that' work?
Thank you.

Do you think 'His son is at the age to understand that' works?

Not a teacher.

[Not a teacher]

"...aged enough to..."

Wines and cheeses can be said to be "aged." Don't say "His son is/has aged enough..."

Don't change the original tz - it's right as it is and more natural than anything else for this use. Though "He is an an age" is possible (not "the" age).

Matthew Wai said:

Do you think 'His son is at the age to understand that' works?

Not a teacher.

Click to expand...

I know 'at the age of...' is correct, but I've never heard/read 'at the age to do something'.
I'd say your version is grammatical but unnatural English.

Barb_D said:

Wines and cheeses can be said to be "aged." Don't say "His son is/has aged enough..."

Click to expand...

Barb_D is right, I wrote #3 just to comment on the right expression ("...aged enough to...", which refers to maturing or ripening), but not to reply to the post about the son and his age.

tzfujimino said:

I've never heard/read 'at the age to do something'.

Click to expand...

About 2,730,000 examples of 'at the age to do' can be found on
https://www.google.com/search?es_sm....2.0....0...1c.1.52.serp..0.2.157.nxdoASF0hs8
What do you think?

Not a teacher.

José Manuel Rosón Bravo said:

Barb_D is right, I wrote #3 just to comment on the right expression ("...aged enough to...", which refers to maturing or ripening), but not to reply to the post about the son and his age.

Click to expand...

That may have been your intention, but anyone reading it may think it was your suggestion on how to amend the original sentence.

Matthew Wai said:

About 2,730,000 examples of 'at the age to do' can be found on
https://www.google.com/search?es_sm....2.0....0...1c.1.52.serp..0.2.157.nxdoASF0hs8
What do you think?

Not a teacher.

Click to expand...

Thank you for the examples.
Yes, it is grammatical.
However, I think "the age" refers to a specific age. So, your version "His son is at the age to understand that" might mean something like "Now he is 10 years old (=at the age of ten), so he can understand that", for instance. It sounds a bit strange, doesn't it? (I understand that "He is at the age to enter high school" is perfectly natural English.) As Barb pointed out in post #5, "He is at an age to understand that" (with the indefinite article) is possible, and it sounds much better to me.