Eldest vs. older

[stone]

English Grammar Tests, Elementary Level

ESL/EFL Test #87 "Common English Errors (3)", question 2

My ......... brother is really nice to me.

(a) eldest
(b) more old
(c) maturest
(d) most older

English Grammar Tests, Elementary Level

ESL/EFL Test #87 "Common English Errors (3)", answer 2

My eldest brother is really nice to me.

Correct answer: (a) eldest

Your answer was: incorrect
My most older brother is really nice to me.
_________________________

Would you please explain the difference between
"eldest brother " and "most older brother "?

Thanks a lot in advance

Stone

[Conchita]

'Most older brother' is not correct, because one-syllable adjectives form their superlative by adding est to the positive form:

old -- the oldest

The only possible and correct option we have here is eldest, which means oldest.

[Linda]

Hello,
Yes, in this case the only possible answer is eldest. However, if 'oldest' was a choice then both would be correct.
Just as an aside, remember that 'eldest' is normally used in front on a noun - and only used with relatives and family members. Whereas, 'old, older and oldest' are used as adjectives of comparison - comparing two things that differ in age.
I hope that helps out a bit more.
Take care,
Linda

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