XX years/months old/pregnant---The boy is "five years" old.

[z7655431]

1. The boy is "five years" old.
2. She is "five months" pregnant.
3. People at "thirty years" old usually have already had a car.
4. At "five months" pregnant, you’ve reached the halfway point of your pregnancy, and hopefully you’re feeling pretty great, because it’s all down hill from here.
What part of speech are the words in quotes above? For me, they're all nouns, and the words old and pregnant are adjectives that post-modify them. However, there're some people who think that these words in quotes are adverbs that modify the adjectives after them. I don't agree with them, because it doesn't make sense in sentence 3 and 4. Could anybody please tell me what's your opinion on this? Thank you!

 

[bhaisahab]

Where did you find those sentences? Sentence #3 is unnatural and #4 is both unnatural and factually incorrect.

 

[z7655431]

Where did you find those sentences? Sentence #3 is unnatural and #4 is both unnatural and factually incorrect.

People at "thirty years" old usually have already had a car.
－I myself wrote this sentence.
At "five months" pregnant, you’ve reached the halfway point of your pregnancy, and hopefully you’re feeling pretty great, because it’s all down hill from here.
－From here: http://www.scarymommy.com/five-months-pregnant/

How about this one?
At thirty years old, he was already earning£ 40000 a year. (Oxford)
What part of speech is "thirty years"?

 

[bhaisahab]

I find that one unnatural, too. I would write "By the age of 30 he was already earning £40,000 a year".

 

[GoesStation]

What's the speech of the words in quotes above?

I think you meant to ask "What part of speech are the words in quotes above?"

 

[z7655431]

What's the speech of the words in quotes above?

I think you meant to ask "What part of speech are the words in quotes above?"

You're right. Sorry! Let me revise them.