Learn Hardcore French: Ton compte est actif; garde aussi ton code. - Your account is active; also keep your code.

Ton is the informal singular possessive (addressing one person you say tu to). For formal or plural, switch to votre and the vous imperative:

Informal: Ton compte est actif ; garde aussi ton code.
Formal/plural: Votre compte est actif ; gardez aussi votre code.

Why is it actif and not active, and what about activé?

Actif agrees with compte, which is masculine singular. If the noun were feminine, you’d use active (e.g., ta carte est active).
Actif describes a state (the account is in an active state).
Activé is the past participle of activer and focuses on the action having been performed (activated). Both est actif and est activé can be seen; choose the one that matches your intended nuance (state vs. result of an action).

Is the semicolon used the same way in French, and do I need a space before it?

Yes, it links two closely related independent clauses, stronger than a comma but lighter than a period. French typography recommends a (non‑breaking) space before ;:

Typographically preferred: … est actif ; garde …
Many informal texts omit the space. After a semicolon, you do not capitalize the next word unless it’s a proper noun.

Why does garde have no final -s?

It’s the tu imperative of a regular -er verb, which drops the final -s: garde (tu), gardons (nous), gardez (vous).

Exception for euphony: before y or en in the affirmative, tu takes an -s: Gardes-en un. But in the negative it goes back to garde: N’en garde pas.

What does garder mean here exactly?

Garder can mean:

Keep/retain physically: Garde le reçu.
Keep something safe/secret: Garde ton code (pour toi).
Sometimes “hang on to/hold onto” or even “remember” by extension in context. Alternatives: conserver (keep), ne partage pas (don’t share), ne communique pas (don’t disclose).

Is code the same as a password?

Often code suggests a PIN or short numeric code (e.g., bank card), while a password is typically mot de passe. You’ll also see code secret or code PIN. Use the term that fits the context:

Bank card: code (secret/PIN)
Online account: mot de passe

Where can I put aussi, and does position change the emphasis?

Neutral: Garde aussi ton code (also keep your code).
End-focus: Garde ton code aussi (slight emphasis on the code being in addition to something else). At the start of a sentence, Aussi in formal writing can mean “therefore” and triggers inversion: Aussi devons-nous vérifier… That’s different from “also.”

Why not C’est actif?

Use c’est mainly before nouns/identifications or to point to something previously mentioned. Here the subject is explicit (ton compte), so Ton compte est actif is the natural structure. C’est actif would mean “It’s active” in a generic, deictic way and doesn’t identify what “it” is.

Why is there no article before compte or code?

Possessive determiners (ton/ta/tes, votre/vos, etc.) replace the article in French. So you say ton code, not le ton code. The possessive agrees with the noun possessed, not with the owner.

How would I say this more politely to a customer?

Votre compte est actif ; veuillez également conserver votre code.
Slightly less formal: Votre compte est actif. Merci de garder votre code confidentiel.

How do you pronounce it?

Approximate IPA: [tɔ̃ kɔ̃t ɛt aktiv ; ɡaʁd osi tɔ̃ kɔd] Notes:

compte = [kɔ̃t] (the letters mpte reduce to a final [t]).
Liaison: est actif pronounces the linking t ([ɛt aktiv]).
Final f in actif is pronounced; final e in code is pronounced [ɔ/ɔd] → here [kɔd].

Could I replace the semicolon with a period or a comma?

Period: perfectly fine and common: Ton compte est actif. Garde aussi ton code.
Semicolon: fine, slightly tighter connection.
Comma: often avoided between two full clauses unless joined by a conjunction (e.g., et), because it can read like a comma splice.

How do I avoid repeating code with a pronoun?

Affirmative imperative: Garde-le. (Keep it.)
Negative imperative: Ne le garde pas. With en when talking about an unspecified amount/instance: Gardes-en un (affirmative, note the added -s), N’en garde aucun (negative).

What changes if the nouns are feminine or plural?

Feminine noun: Ta carte est active ; garde aussi ton code.
Plural nouns: Tes comptes sont actifs ; garde aussi tes codes.
Formal/plural: Vos comptes sont actifs ; gardez aussi vos codes.

Any spelling pitfalls I should watch for?

Yes:

compte (account) vs conte (tale/story) vs comte (count, the title). Only compte fits here.
Don’t add an article before a possessive: ton code, not le ton code.