Les chevaux du voisin jouent près des vaches tous les matins.

The noun cheval (horse) has an irregular plural in French:

• singular: un cheval
• plural: des chevaux

Many French nouns ending in -al form the plural in -aux, for example:

• un animal → des animaux
• un journal → des journaux

So chevals is incorrect; the only correct plural is chevaux.

French doesn’t use the ’s possessive structure. Instead, it uses a “noun + de + possessor” structure:

• les chevaux du voisin = literally “the horses of the neighbor”

So:

• les chevaux du voisin = the neighbor’s horses
• les chevaux de mon voisin = my neighbor’s horses
• la maison du professeur = the teacher’s house

The possessor (here du voisin) almost always comes after the thing possessed (les chevaux), not before like in English.

Du is a contraction of de + le:

• de + le voisin → du voisin

In French, these contractions are mandatory:

• de + le → du
• de + les → des

So:

• les chevaux du voisin (not de le voisin)
• près des vaches (not près de les vaches)

Voisin means male neighbor and is masculine. Voisine is the feminine form, meaning female neighbor.

In the sentence, we are talking about a male neighbor, so we use the masculine:

• du voisin = of the (male) neighbor
  If it were a female neighbor, we would say:
• de la voisine = of the (female) neighbor
  (and there is no contraction with de + la)

The subject is Les chevaux du voisin. The real grammatical subject is chevaux, which is plural. In French, the verb must agree with the subject in number and person.

The verb jouer (to play), present tense:

• il / elle / on joue (singular)
• ils / elles jouent (plural)

Here we mean “the horses they play,” so we need the third person plural form jouent.

Près de means near or close to.

Because près is always followed by de, and then by the noun:

• près de la maison = near the house
• près du lac (de + le) = near the lake
• près des vaches (de + les) = near the cows

In près des vaches, des is the contraction of de + les, not the indefinite article des.

Both can mean near, but there’s a nuance:

• près de: generally “near / close by”, sometimes a bit vague about exact position.
• à côté de: literally “beside / next to”, usually closer, side‑by‑side.

In this sentence, près des vaches just says the horses are in the area near the cows, not necessarily right next to them.

In French, you almost always need an article before a noun. After près de, you must use de + article.

• près de + les vaches → près des vaches

You cannot leave out the article here; près vaches would be ungrammatical. French generally avoids bare nouns where English can say just “near cows”.

Both express a regular habit:

• tous les matins = every morning, all mornings
• chaque matin = each morning

The difference is subtle:

• tous les matins feels a bit more like a repeated routine over a period (a bit more common in speech).
• chaque matin can sound slightly more individualizing (each separate morning), sometimes a little more formal or written.

In everyday conversation, tous les matins is very natural for a regular habit like this.

The word matin (morning) is masculine:

• un matin = a morning

When you say tous les (“all the / every”), the noun must be plural:

• tous les matins = literally “all the mornings” → “every morning”

So we need:

• tous (masculine plural)
• les (plural article)
• matins (plural noun)

Yes. In French, time expressions are quite flexible. All of these are correct:

• Les chevaux du voisin jouent près des vaches tous les matins.
• Tous les matins, les chevaux du voisin jouent près des vaches.
• Les chevaux du voisin jouent tous les matins près des vaches.

The meaning stays the same: it’s a regular morning habit. Placing tous les matins at the start can emphasize the time a bit more.

Les is simply the plural definite article in French, used for both genders:

• le = the (singular masculine)
• la = the (singular feminine)
• les = the (plural, masculine or feminine)

So:

• les chevaux (masculine plural)
• les vaches (feminine plural)
• les matins (masculine plural)

The form les doesn’t change between masculine and feminine; it only marks plural.

Yes, there are a couple of common points:

• Les chevaux: normally no liaison; pronounce lé-che-VO.
• près des vaches: often you’ll hear a liaison: prè *dé(z) vaches, with a /z/ sound linking *des and vaches.
• tous les matins: in most everyday speech, tous is pronounced like tou (no final /s/), and there is usually no liaison: tou lé matin.

So a natural pronunciation would be something like:
Lé chevÔ du voa-zin jouent prè dé(z) vache tou lé matin.