"Here are the pants I ordered."

Translation: Voici les pantalons que j'ai commandés.

[BaiShann]

Is is plural? How does one know that the speaker ordered more than one pair of pants? Just askin'.

[Ripcurlgirl]

True. It should also accept "Voici le pantalon que j'ai commandé".

[ocelotish]

It does as of March 2018

[Sitesurf]

It does!

[JosephT.Madawela]

It does not as of october 2018

[Sitesurf]

So, your sentence probably had another error.

[JannaRyan]

Yep, that was my issue too.

[LynnMoelle]

why "que" instead of "ce" or "le"?

[Ripcurlgirl]

ce only means "that" when it is used as a demonstrative adjective as in "ce garçon" → that boy. le is either the masculine definite article meaning "the" or the masc. direct object meaning "it" or "he".

However, "that" here is a relative pronoun that is usually left out of English sentences.
"Here are the pants" point 1, "that" (the relative pronoun) "I ordered" point 2. The 2 points are related but the French sentence requires the relative pronoun "que".

[isa867427]

do you make the past participle plural if the pants are plural? i thought it was only with the être verbs that you change the past participle according to gender and singular/plural?

[Ripcurlgirl]

Yes, but, for avoir compound verbs, this is only the case when the direct object precedes the verb.