"I have never seen such a big dolphin."

Translation: Je n'ai jamais vu de dauphin aussi grand.

[dVMP6]

Why DE dauphin?

[thetomgentry]

In most cases, when a verb other than être is negated, indefinite and partitive articles before the object become « de » .

[Lisa_Lyons]

I think you should be able to get by with "un" here because it's specifying what kind of dolphin you've never seen. (Whereas "I've never seen a dolphin" should definitely be "de" because you've never seen ANY dolphin at all.) If I get this sentence again, I'm going to try it with "un" and see what happens.

[lucy163354]

Un was not accepted, though I agree it makes more sense. The English means one dolphin, not any dolphin.

[TimmyKilminster]

Un is accepted June 2021.

[stupefaite]

I got accepted for je n'ai jamais vu un dauphin aussi gros, but I wonder about un aussi gros dauphin.

Previously I got right Je n'ai jamais vu un aussi gros moustique https://forum.duolingo.com/comment/42065528

[rose830046]

un accepted for me

[marylanes]

why is grand - an adjective of size - placed after the noun?

[c5nest]

Why does Duolingo require "de" in this case but present the sentence: "Je n'ai je n'ai jamais vu une grotte aussi grande." as correct?

[N.Hilary]

"Je n'ai jamais vu un aussi grand dauphin" Accepted.

[Sakallitavshan]

But Je n'ai jamais vu de aussi grand dauphin

[Nalupilot1]

That's the sentence i had and it was marked incorrect. Still don't understand why "un" in place of "de" makes it alright to put the these "intensifier" adjectives before the noun (as they are normally placed).

[Thomas45248]

It would have to be d'aussi.

[Sakallitavshan]

Shouldn't the adjective grand come before the noun (dauphin)

[Ofer862867]

Can we say "si" instead of "aussi"?

[Daniel589120]

Je n'ai jamais vu de dauphin si grand. <--accepted.