Fraction: a half vs one half; a third vs one third; a fourth vs one fourth

1/ 1/2 can be read “a half” or “one half”.
1/3 can be read “a third” or “one third”
so can 1/4 be read “a fourth” or “one fourth”?

2/ Despite its antiquity, certain aspects of its construction make it one of the truly wonders of the world

=> I don’t understand why they use truly (an adverb) here. Is the sentence wrong?

Hi Nessie

  1. Yes

  2. No, that word order doesn’t work. However, if you moved the word truly as follows, it would be OK:
    Despite its antiquity, certain aspects of its construction make it truly one of the wonders of the world.
    .

Nessie,

You incorrectly copied the sentence. The actual sentence is “truly great”. This would utilize “truly” as an adverb to modify the adjective “great”.

“Despite its antiquity, certain aspects of its construction make it one of truly great wonders of the world.”