1. He grew 25 cm last year.
2. He grew by 25 cm last year.
(Is 'by' deleted in Sentence 1? What is the meaning of 'by' here?)
Hmmmm! I don't know.
I'd use the first sentence, but not the second.
2. He grew by 25 cm last year.
(Is 'by' deleted in Sentence 1? What is the meaning of 'by' here?)
I'd use the first sentence, but not the second.