La méditation quotidienne l'aide à garder une humeur plus stable.

l' is a direct object pronoun that stands for le (him/it, masculine) or la (her/it, feminine).

• In front of a verb that starts with a vowel or a silent h, le and la become l' (this is called elision):
  
  • le aide / la aide → l'aide
• It refers to a person or thing mentioned earlier in the context, e.g. “It helps her to keep a more stable mood” or “It helps him… ”.
• From l' alone, you cannot tell if it’s masculine or feminine; only the context tells you.

The word order is:
La méditation quotidienne (subject) + l' (object pronoun) + aide (verb).

The verb aider is conjugated in the third person singular (il/elle/on aide) because the subject la méditation quotidienne is singular.

• Subject: la méditation quotidienne → “daily meditation” (one thing)
• So the verb must be singular: aide
• If the subject were plural, you would use aident:
  
  • Les exercices quotidiens l’aident à garder une humeur plus stable.
    “The daily exercises help her/him keep a more stable mood.”

In French, object pronouns usually go before the conjugated verb, unlike in English.

Word order pattern:
Subject + object pronoun + conjugated verb

So you get:

• La méditation quotidienne l’aide…
  and not
• ✗ La méditation quotidienne aide l’…

Some common pronouns that go before the verb: me, te, le, la, l’, nous, vous, les, lui, leur.
Example:

• La méditation m’aide. – “Meditation helps me.”
• La méditation l’aide. – “Meditation helps him/her/it.”

The standard structure with aider when followed by a verb is:

aider quelqu’un à + infinitive

So you say:

• aider quelqu’un à faire quelque chose – “to help someone to do something”

In this sentence:

• (La méditation) l’aide à garder…
  
  • l’ = the person helped
  • à = the preposition used with aider
  • garder = the infinitive (“to keep”)

Using de here (aide de garder) would be incorrect in standard French.

After aider à, the next verb stays in the infinitive:

• aide à garder = “helps (her/him) to keep”

In English you also keep it in the base form:

• “helps to keep”
• “helps keep”

French does not conjugate the second verb in this structure. So you cannot say:

• ✗ l’aide à garde
  It must stay:
• l’aide à garder

Both are possible, but the nuance is slightly different:

• garder une humeur plus stable
  
  • Literally “to keep a more stable mood”
  • Sounds more general/descriptive, like talking about mood in a broader sense.
• garder son humeur plus stable
  
  • Literally “to keep her/his mood more stable”
  • Puts more emphasis on the person’s own mood as something they possess.

French often uses the article (un/une/le/la) where English would automatically use a possessive (“his/her/its”), especially with things like body parts or states. So une humeur plus stable is very natural here.

No. humeur is a false friend:

• humeur = mood, emotional state
  
  • être de bonne humeur – “to be in a good mood”
  • changer d’humeur – “to change mood”
• English humor (what makes you laugh) is usually humour / humour comique in French, or you’d talk about avoir de l’humour (“to have a sense of humor”).

So in this sentence, humeur refers to emotional stability, not funniness.

Adjectives in French must agree in gender and number with the noun they describe.

• méditation is feminine singular → la méditation
• The base adjective is quotidien (“daily”)
• Feminine form: quotidienne (add -ne and -e)

So:

• la méditation quotidienne – correct
• ✗ la méditation quotidien – incorrect, gender mismatch

If the noun were masculine, you’d use quotidien:

• le rituel quotidien – “the daily ritual”

Here plus is used for a comparative of superiority (“more …”):

• plus + adjective = “more + adjective”
• une humeur plus stable = “a more stable mood”

Other examples:

• plus calme – more calm
• plus intéressant – more interesting

You only say plus de when you compare quantities (more of something), not adjectives:

• plus de temps – more time
• plus de problèmes – more problems

So plus stable, not ✗ plus de stable.

You can say it, but it sounds less natural and a bit heavier than using the pronoun.

• La méditation quotidienne l’aide à garder une humeur plus stable.
  
  • Very natural, compact.
• La méditation quotidienne aide à garder une humeur plus stable pour elle.
  
  • Grammatically possible, but:
    • pour elle sounds more like “for her benefit” or “for her” in a more external way.
    • It doesn’t function as a direct object of aide; it’s a separate complement.

If you mean that she is the one being helped, the most idiomatic choice is to use the object pronoun l’. The pour elle version would be more like saying “Daily meditation helps to keep a more stable mood for her,” slightly changing the focus.