Le professeur demande à chaque élève de lire un paragraphe de son résumé à voix haute.

The pattern is:

demander à quelqu’un de + infinitive

• demander à = to ask (someone)
• quelqu’un = the person asked
• de + infinitive = what you are asking them to do

So:

• Le professeur demande à chaque élève de lire…
  = The teacher asks each student to read…

This is the standard way in French to say “ask someone to do something.”

In French, with demander meaning to ask (someone), the person you ask must be introduced by à:

• demander quelque chose à quelqu’un
  to ask someone for something / to ask someone something

So you say:

• Le professeur demande quelque chose à chaque élève.
  The teacher asks each student for something.

You cannot say « demande chaque élève » without à; that would be incorrect French, because the verb needs the preposition here to introduce the indirect object (the person).

With demander à quelqu’un de + infinitif, the correct preposition before the infinitive is de, not à or pour:

• demander à quelqu’un de faire quelque chose
  to ask someone to do something

So:

• demander à chaque élève de lire ✅
• demander à chaque élève à lire ❌
• demander à chaque élève pour lire ❌

à is already used before the person (à chaque élève), and de is the one that introduces the action being requested.

Because lire is part of the structure demander à quelqu’un de + infinitif.

If you conjugated it:

• Le professeur demande à chaque élève lit… ❌

that would be ungrammatical in French. After de, you must use the infinitive:

• demande à chaque élève de lire… ✅
  = asks each student to read…

chaque élève = each student (as a grammatical subject or object on its own)

Here, however, élève is not a subject but an indirect object of demander, so it needs the preposition à:

• Le professeur demande à chaque élève…
  The teacher asks each student…

The nuance of chaque is that the action applies individually to every student, one by one, rather than to the group as a whole. It’s like saying “each student (in turn)” rather than “all the students.”

By default, in this structure it refers to each student’s own résumé:

• Le professeur demande à chaque élève de lire un paragraphe de son résumé…
  is naturally understood as their own summary (the one each student wrote).

French often uses son / sa / ses to refer to the logical owner in context, even when multiple people are involved. So here:

• chaque élève → son résumé
  = each student → his/her own résumé

If the sentence meant the teacher’s résumé, it would usually be made explicit:

• …de lire un paragraphe du résumé du professeur.

No. In French:

• un résumé = a summary, a short version of a text, story, article, etc.

The English word “résumé” (meaning CV) was borrowed long ago, but in modern French, for a CV you say:

• un CV or un curriculum vitæ,
  not un résumé.

So in this sentence, « son résumé » means “his/her summary (of a text)”, not a job CV.

Literally:

• voix = voice (feminine)
• haute = high, loud (feminine form of haut)
• à voix haute = in a high/loud voice

Idiomatically, « lire à voix haute » means:

• to read out loud / aloud, so that others can hear.

This is the usual, natural way to say “out loud” in French. A very common synonym is « lire à haute voix » (same meaning, just the words reversed).

Because voix is feminine singular, so the adjective haut must agree:

• masculine singular: haut
• feminine singular: haute

Since voix is feminine:

• une voix haute ✅
• une voix haut ❌

So « à voix haute » simply shows normal adjective agreement in gender and number.

Yes, grammatically that would be fine, but it would change the meaning:

• lire un paragraphe de son résumé
  = to read one paragraph from his/her summary (only part of it)

• lire son résumé
  = to read his/her whole summary

The original sentence emphasizes that each student reads only one paragraph, not the entire summary.

It’s usually placed at the end for a natural rhythm, but it can move a bit:

• Le professeur demande à chaque élève de lire un paragraphe de son résumé à voix haute. ✅ (most natural)
• Le professeur demande à chaque élève de lire à voix haute un paragraphe de son résumé. ✅ (also correct, a bit more emphasis on reading out loud)

You wouldn’t normally break up « à voix haute » or put it far away from « lire », since it’s an adverbial phrase modifying lire.

Yes, there is a liaison between voix and haute:

• à voix haute → pronounced roughly: [a vwa zot]

Details:

• à → [a]
• voix → [vwa]
• liaison: final x in voix becomes a [z] sound before a vowel sound
• haute → [ot] (the h is silent, not aspirated)

So you link them: voix‿haute → [vwazot].

French present tense (il demande) can cover several English present-time meanings:

• He asks (simple present)
• He is asking (present continuous)
• He does ask (emphatic)

So:

• Le professeur demande à chaque élève de lire…

can be translated depending on context as:

• The teacher asks each student to read…
  or
• The teacher is asking each student to read…

The French form doesn’t change; context decides which English version feels best.