Learn Hardcore French: Le chat reste au chaud dans la maison.

The verb rester means “to stay” or “to remain,” implying that the cat continues to be somewhere by choice or habit. If you said Le chat est au chaud dans la maison, it would simply state “The cat is warm in the house” without the nuance of “staying” warm there. Rester adds the idea of persistence in that cozy spot.

What does au chaud mean, literally and idiomatically?

Literally, au is the contraction of à le (“to the” or “at the”) and chaud means “warm.” So au chaud is “at the warmth” or “in the warmth.” Idiomatically, it means “in a warm/cozy place” or “keeping warm.”

How does the contraction au work in French?

In French, whenever à (to/at) meets the masculine singular definite article le (the), they fuse into au.
Examples:
• Je vais au cinéma. (not à le cinéma)
• Je donne un cadeau au garçon. (not à le garçon)
This contraction is mandatory.

Why use dans la maison? Could I say à la maison? What’s the difference?

Dans means “inside,” so dans la maison emphasizes being within the walls of the house.
À la maison means “at home” or simply “at the house,” more generally.
Both are correct:
• Le chat reste au chaud à la maison. (The cat stays warm at home.)
• Le chat reste au chaud dans la maison. (Emphasizes that the cat is literally inside.)

Why is it le chat instead of un chat?

Le is the definite article (the), indicating a specific cat known to speaker and listener. Un is the indefinite article (a/an), which introduces something general or unspecified. Here we’re talking about the cat we’ve been following or observing.

How do I know that maison is feminine and must take la?

French noun genders often must be memorized. Maison is feminine, so it takes la maison. A helpful tip: many nouns ending in -son (raison, prison, leçon…) are feminine. When unsure, always check a dictionary.

How do I pronounce au chaud? Are there silent letters or liaisons?

Au is pronounced /o/.
Chaud is pronounced /ʃo/.
There’s no liaison between au and chaud because chaud begins with a consonant sound (/ʃ/). So you say /o ʃo/—almost like “oh-show” but with one “oh.”

Can I use another verb instead of rester, like demeurer or habiter?

Demeurer also means “to remain,” but it’s more formal or literary: Le chat demeure au chaud is correct but less common in speech.
Habiter means “to live” rather than “to stay warm”: Le chat habite dans la maison simply states that it lives in the house.
Choose based on nuance: rester for “stay,” demeurer for a formal “remain,” être for a neutral state, and habiter for “reside.”