Ces chaussures sont en solde aujourd'hui.

Ces is the plural demonstrative adjective, used before a plural noun. It can mean either these or those.

French usually does not insist on the near/far distinction as much as English does. So ces chaussures can mean these shoes or those shoes, depending on context.

Because chaussures is plural.

The demonstrative forms are:

• ce
  • masculine singular noun
• cet
  • masculine singular noun starting with a vowel sound
• cette
  • feminine singular noun
• ces
  • plural noun

Since chaussures is plural, the correct form is ces.

Chaussure is feminine: une chaussure.

Its gender matters in the singular, where you would say cette chaussure. But in the plural, French uses ces for both masculine and feminine nouns, so the gender is not visible in ces chaussures.

Because ces already functions as a determiner.

In French, you normally do not stack a demonstrative and an article together before the same noun. So you say:

• ces chaussures not
• les ces chaussures

This works similarly to English: you say these shoes, not the these shoes.

Sont is the they are form of être.

The subject is ces chaussures, which is third-person plural, so the verb must also be plural:

• cette chaussure est = this shoe is
• ces chaussures sont = these shoes are

So sont agrees with the plural noun chaussures.

En solde is a fixed expression meaning on sale or discounted when talking about an item.

So you say:

• Ces chaussures sont en solde.

But les soldes refers to the sales as an event or sales season:

• Les soldes commencent demain. = The sales start tomorrow.

So:

• en solde = on sale
• les soldes = the sales

Here en is part of a fixed expression. You should learn être en solde as a chunk meaning to be on sale.

French often uses en in set phrases where English uses an adjective or a different construction. So it is better not to translate it word-for-word, but to remember the whole expression:

• être en solde = to be on sale

Yes. En promotion is also very common.

The difference is roughly this:

• en solde often suggests sale-price items, especially during a sales period
• en promotion is broader and can mean any promotional discount

In everyday use, both can often work, but en solde is especially common for store-sale wording.

Putting aujourd'hui at the end is very natural in French.

French time expressions are often placed at the beginning or the end of a sentence:

• Ces chaussures sont en solde aujourd'hui.
• Aujourd'hui, ces chaussures sont en solde.

Both are correct. The version with aujourd'hui at the end sounds very normal and straightforward.

A careful pronunciation is approximately:

say shoh-SYUR sohn-tahn sold oh-zhoor-DWEE

A few useful points:

• ces sounds like say
• chaussures sounds roughly like shoh-SYUR
• sont has a nasal vowel, so the n is not fully pronounced
• there is a liaison between sont and en, so it sounds like sohn-tahn
• aujourd'hui sounds roughly like oh-zhoor-DWEE

So the sentence flows something like:

say shoh-SYUR sohn-tahn sold oh-zhoor-DWEE

Yes, but it means something slightly different in structure.

• Ces chaussures sont en solde aujourd'hui. = These shoes are on sale today.
• Ce sont des chaussures en solde aujourd'hui. = These are shoes that are on sale today or They are shoes on sale today

The original sentence starts directly with the noun phrase ces chaussures, which is the most natural way to say These shoes are on sale today. The ce sont version is possible, but it is not the most direct choice here.

Usually, no. Ces and ses are normally pronounced the same.

That means French learners often have to rely on meaning and spelling:

• ces chaussures = these/those shoes
• ses chaussures = his/her shoes

So in writing, the difference is very important, even though the pronunciation is usually the same.