Learn Hardcore French: Ces souvenirs de ce jour magnifique me donnent de la joie. - These memories of this wonderful day give me joy.

Masculine singular: ce (or cet before a vowel sound) → ce jour, cet homme
Feminine singular: cette → cette femme
Plural (masc. or fem.): ces → ces souvenirs, ces idées

Because souvenirs is plural, you must use ces.
Ce souvenir = this memory (one).
Ces souvenirs = these memories (more than one).

Why is souvenirs plural? Could it be singular souvenir instead?

It could be singular, but the meaning changes slightly:

Ce souvenir de ce jour magnifique me donne de la joie.
→ This memory of that wonderful day gives me joy. (focusing on one particular memory)
Ces souvenirs de ce jour magnifique me donnent de la joie.
→ These memories of that wonderful day give me joy. (various memories from that same day)

Also, note that un souvenir in French can mean:

a memory (mental image/remembrance), or
a souvenir in the tourist sense (an object you bring back), depending on context.

Here, because it’s de ce jour magnifique, it clearly means memories of that day, not tourist trinkets.

What exactly does de ce jour magnifique mean? Is de more like “of” or “from” here?

De ce jour magnifique can be understood as both:

memories of this wonderful day
memories from this wonderful day

The preposition de is very flexible in French. Here, it expresses a link of origin or association between:

souvenirs (memories)
and ce jour magnifique (that specific day)

So it’s roughly “memories that come from / belong to / are about that day.”
Both of and from are acceptable ways to think of it in English.

Why is it ce jour magnifique and not ce magnifique jour? Where does magnifique normally go?

Most French adjectives come after the noun, and magnifique is usually one of them:

un jour magnifique = a wonderful day (neutral, standard word order)

You can say un magnifique jour, but that sounds:

more literary, poetic, or emotional
less common in everyday speech

So:

ce jour magnifique = natural and standard
ce magnifique jour = possible, but more stylistic / expressive

In your sentence, ce jour magnifique is the most neutral, everyday phrasing.

What does me donnent literally mean, and why is it plural?

Me donnent comes from the verb donner (to give).

donnent is the 3rd person plural present form (they give)
me is the indirect object pronoun (to me)

So me donnent ≈ give me.

The verb is plural because the subject is ces souvenirs (these memories), which is plural:

Ce souvenir me donne de la joie. → This memory gives me joy. (singular: donne)
Ces souvenirs me donnent de la joie. → These memories give me joy. (plural: donnent)

French verbs must agree in number (and person) with the subject, not the object.

Why does me come before donnent? In English we say “give me”, not “me give”.

In French, object pronouns like me, te, lui, nous, vous, leur normally go before the conjugated verb:

Ils me donnent de la joie. → They give me joy.
Il me parle. → He talks to me.
Tu nous aides. → You help us.

You cannot say donnent me in standard French.

If the verb is in an infinitive construction, the pronoun goes before the infinitive:

Ces souvenirs peuvent me donner de la joie.
(These memories can give me joy.)

But with a simple present like your sentence, the pattern is:

Subject + pronoun + verb + rest of the sentence
→ Ces souvenirs me donnent de la joie.

Why is it de la joie and not just la joie or du joie?

De la joie uses the partitive article:

de + le = du (masculine)
de + la = de la (feminine)
de + l’ = de l’ (before vowel)

Since joie is feminine, you get de la joie.

The partitive often translates as some or an unspecified amount:

Ils me donnent de la joie. → They give me (some) joy.

If you said la joie, it would sound like you’re talking about joy in general, in a more abstract way:

La joie est importante. → Joy is important.

And du joie is simply wrong, because joie is not masculine. The correct pair is:

du bonheur (masculine)
de la joie (feminine)

Could I say Ces souvenirs de ce jour magnifique me rendent heureux / heureuse instead? What’s the difference from me donnent de la joie?

Yes, you can say:

Ces souvenirs de ce jour magnifique me rendent heureux. (if you are male)
Ces souvenirs de ce jour magnifique me rendent heureuse. (if you are female)

Me rendre + adjective means to make me + adjective:

me rendent heureux / heureuse → make me happy
me rendent triste → make me sad

The nuance:

me donnent de la joie
→ focuses on the joy they give you, as a “thing” or feeling you receive.
me rendent heureux / heureuse
→ focuses on your resulting state (you end up happy).

Both are correct; the choice is more about style and emphasis than grammar.

What’s the difference between joie and bonheur in French?

Both relate to happiness, but they’re not identical:

la joie
- more immediate, emotional, often tied to a specific moment or event
- e.g. la joie de le revoir = the joy of seeing him again
le bonheur
- more lasting, like happiness, well‑being, sometimes good fortune
- e.g. Elle a trouvé le bonheur. = She has found happiness.

In your sentence, de la joie fits well because these memories create moments of joy when you think of them.
You could rephrase with bonheur, but it would slightly change the feel: more like they contribute to your overall happiness.

How do you pronounce souvenirs and donnent? Are the final letters silent?

Yes, some final letters are silent here:

souvenirs → roughly /suv(ə)niʀ/
- final s is silent in isolation: souvenir(s) ends with an [ʀ] sound
- in this sentence there’s no liaison after souvenirs because de starts with a consonant
donnent → /dɔn/
- the -ent ending in ils donnent / elles donnent is not pronounced
- it sounds exactly like il donne in spoken French

So the key audible parts are:

souvenirs → sou‑ve‑nir (with a French r at the end)
donnent → don (short “o” as in don in British English)