Au refuge, Marie regarde un chiot calme, tandis que sa sœur préfère une chienne plus vive.

Au is the contraction of à + le.

• à = at / to / in
• le = the (masculine singular)
• à le becomes au

So:

• au refuge = at the shelter

This contraction is required in standard French.

Related forms:

• à + le = au
• à + les = aux
• à + la = à la
• à + l’ = à l’

Because refuge is masculine singular, French uses au refuge.

In this sentence, refuge most naturally means an animal shelter.

French refuge can also mean a general shelter or safe place, depending on context, but with chiot and chienne in the sentence, it clearly suggests a place where animals are kept and adopted.

They are both in the present tense, third-person singular, because the subjects are singular:

• Marie regarde = Marie looks at / is looking at
• sa sœur préfère = her sister prefers

These come from:

• regarder → je regarde, tu regardes, il/elle regarde
• préférer → je préfère, tu préfères, il/elle préfère

So the -e ending here matches Marie and sa sœur, both singular subjects.

These words refer to different kinds of dogs:

• un chiot = a puppy
• un chien = a male dog or sometimes just dog in a general sense
• une chienne = a female dog

So in this sentence:

• un chiot calme = a calm puppy
• une chienne plus vive = a livelier female dog

A learner should notice that French often distinguishes the animal’s sex more explicitly than English does.

Because these nouns have different grammatical genders:

• chiot is masculine → un chiot
• chienne is feminine → une chienne

In this case, the grammatical gender also matches biological sex:

• chiot is grammatically masculine
• chienne is grammatically feminine

This matters because articles and adjectives must agree with the noun.

Because the possessive adjective agrees with the thing being possessed, not with the owner.

Here, the possessed noun is sœur, which is feminine:

• sa sœur = his/her sister

French possessives work like this:

• mon / ton / son with masculine singular nouns
• ma / ta / sa with feminine singular nouns
• mes / tes / ses with plural nouns

So even if the sister belongs to Marie, or to someone male, you still say sa sœur because sœur is feminine.

Tandis que means while, whereas, or while on the other hand, depending on context.

Here it introduces a contrast between the two sisters’ preferences:

• Marie looks at a calm puppy,
• tandis que her sister prefers a livelier female dog.

So it does more than just join two actions. It suggests contrast.

It is similar to:

• while
• whereas

It is stronger and more formal than simply using et (and), and more descriptive than mais (but) in this kind of sentence.

In French, most adjectives come after the noun.

So:

• un chiot calme = a calm puppy

That is the normal order for many descriptive adjectives, especially ones describing:

• character
• color
• shape
• category
• physical qualities

Some common adjectives do go before the noun, but calme is normally placed after it.

Because the adjective must agree with chienne, which is feminine singular.

The base adjective is:

• masculine: vif
• feminine: vive

So:

• un chien vif
• une chienne vive

With plus, the agreement still stays:

• une chienne plus vive = a livelier female dog

French adjectives usually agree in gender and number with the noun they describe.

Yes. Plus vive is a comparative form.

• vive = lively / energetic
• plus vive = more lively / livelier

French often uses plus + adjective to make a comparison.

Here, the comparison is somewhat implicit. It most likely means the sister prefers a dog that is more lively than the calm puppy Marie is looking at, or simply more lively in general.

The full comparison could be made explicit with que:

• plus vive que le chiot = livelier than the puppy

But French does not always need to say the second part if it is obvious from context.

Πis a ligature in French, combining o and e in writing.

In sœur, it is part of the standard spelling. You simply learn the word as:

• sœur = sister

The plural is:

• sœurs

This spelling appears in a number of French words, though not in every word with those sounds.

The verb is préférer. In some forms, the accent pattern changes:

• je préfère
• tu préfères
• il/elle préfère

but:

• nous préférons
• vous préférez

This is a common pattern in some -é...e verbs, where the é in the stem changes to è in certain forms to reflect pronunciation.

So préfère is not random spelling; it follows a conjugation pattern.

Yes. In this sentence, regarder means to look at or to watch something directly.

That is an important difference from English:

• French regarder quelque chose = to look at something
• French does not need a separate word like at

So:

• Marie regarde un chiot = Marie is looking at a puppy

By contrast, English usually requires look at.

The comma helps separate the two parts of the sentence:

• Au refuge, Marie regarde un chiot calme
• tandis que sa sœur préfère une chienne plus vive

This makes the contrast clearer and makes the sentence easier to read. In French, punctuation with linking expressions like tandis que is often used much like in English when two related clauses are being contrasted.