Learn Hardcore French: Je suis content que tu aies réussi ton examen de biologie. - I am happy that you have passed your biology exam.

Je suis content que tu aies réussi... → correct in standard French
- aies réussi = present subjunctive of avoir
  - past participle
Je suis content que tu as réussi... → sounds wrong to native speakers in standard French (though you may hear it in casual speech)

General rule:
Emotion / judgment / doubt + que + a change of subject → subjunctive

Examples:

Je suis triste que tu partes. (I’m sad that you’re leaving.)
Je suis surpris qu’il ait refusé. (I’m surprised he refused.)

What exactly is aies réussi in terms of tense and mood?

Aies réussi is:

Mood: subjunctive
Tense: past (passé) subjunctive

It’s formed with:

present subjunctive of avoir
- past participle
  - tu aies (present subjunctive of avoir)
  - réussi (past participle of réussir)

Other forms of the past subjunctive with réussir:

que j’aie réussi
que tu aies réussi
qu’il / elle / on ait réussi
que nous ayons réussi
que vous ayez réussi
qu’ils / elles aient réussi

Could I say Je suis content parce que tu as réussi ton examen de biologie instead? What’s the difference?

Yes, you can, and it’s perfectly correct:

Je suis content que tu aies réussi...
- More neutral/standard when using the structure être + adjective + que
- Automatically triggers the subjunctive (aies réussi)
Je suis content parce que tu as réussi...
- Uses parce que (“because”) with the normal indicative (tu as réussi)
- Sounds a bit more like you’re explaining the reason for your happiness

In practice, both sentences mean almost the same thing; the first emphasizes the emotional reaction with the typical que + subjunctive structure, the second is more straightforward “I’m happy because X happened.”

When do I have to use the subjunctive after être content que and when not?

With être content que, you almost always use the subjunctive, because it expresses an emotion about another person’s action:

Je suis content que tu aies réussi.
Elle est contente que nous venions.

However, if there is no change of subject, French usually switches to an infinitive instead of que + subjunctive:

Je suis content d’avoir réussi mon examen.
- Same subject (je) for “to be happy” and “to have passed”
- So: de + infinitive (d’avoir réussi), not que j’aie réussi

Compare:

Different subjects → Je suis content que tu aies réussi.
Same subject → Je suis content d’avoir réussi.

Why is it content and not contente? When would it be contente?

The adjective agrees with the subject of the verb être, which is je.

If the speaker is male:
- Je suis content que...
If the speaker is female:
- Je suis contente que...

In writing, you’d show the difference:

Un homme : Je suis content que tu aies réussi ton examen.
Une femme : Je suis contente que tu aies réussi ton examen.

In speech, they’re pronounced almost the same, but in careful speech you might hear the final -t in contente.

What is the difference between content and heureux here?

Both mean roughly happy, but:

Content
- Everyday, neutral, slightly milder
- Very common in spoken French
- Like “glad” or “pleased”
Heureux / heureuse
- A bit stronger or more formal
- Can sound slightly more “serious” or “elevated”
- Like “really happy” or “delighted”

Both are possible:

Je suis content que tu aies réussi ton examen. (normal everyday tone)
Je suis très heureux que tu aies réussi ton examen. (stronger enthusiasm / more formal)

Why is it réussi ton examen and not réussi à ton examen?

Both exist in French:

Réussir un examen (without preposition)
- Very common, maybe the most neutral:
- Il a réussi son examen.
Réussir à un examen (with à)
- Also correct, often felt as a bit more formal / schoolish:
- Il a réussi à son examen.

So you could also say:

Je suis content que tu aies réussi à ton examen de biologie.

The version in your sentence (réussi ton examen) is completely standard.

Why is it ton examen de biologie and not ton examen en biologie?

With school subjects and exams, French normally uses de:

un examen de biologie
un cours de biologie
un devoir de maths
un contrôle d’histoire

En is used differently, for example:

être bon en biologie (to be good at biology)
avoir un diplôme en biologie (to have a degree in biology)

So un examen de biologie is the standard way to say “a biology exam.”

Can I just say Je suis content que tu aies réussi ton examen and leave out de biologie?

Yes.

Je suis content que tu aies réussi ton examen.
- Perfectly correct and often what people say if the subject is clear from context.

Adding de biologie simply adds detail about which exam you mean.

Why is it ton examen and not de ton examen after réussi?

Because réussir is normally used as a direct transitive verb with un examen:

réussir quelque chose → to pass / succeed at something
- réussir son examen
- réussir un concours

When you say réussir de + noun, it means something different and is rare/specialized (e.g. réussir de beaux dessins = to manage to make beautiful drawings).

So here the direct object is ton examen, with no preposition: réussir ton examen.

Could I replace tu with vous? How would the sentence change?

Yes. You’d need to change both the pronoun and the verb form:

Informal / singular:
- Je suis content que tu aies réussi ton examen de biologie.
Formal or plural:
- Je suis content que vous ayez réussi votre examen de biologie.

Note the changes:

tu aies → vous ayez (subjunctive of avoir)
ton examen → votre examen for politeness or plural

If I’m talking about myself, how do I say “I’m happy that I passed my biology exam”?

You have two natural options:

With infinitive (preferred in French when the subject is the same):
- Je suis content d’avoir réussi mon examen de biologie.
With que + subjunctive (grammatically possible, but less natural here):
- Je suis content que j’aie réussi mon examen de biologie.
- This is usually avoided; French prefers the de + infinitive structure in same-subject cases.

So in real life, people overwhelmingly say:

Je suis content d’avoir réussi mon examen de biologie.