Avant la promenade, j’attache la médaille au collier de la chienne.

Because je drops its final e before a vowel sound. This is called elision.

• je + attache → j’attache
• The apostrophe replaces the missing e

You see this very often in French:

• j’aime
• j’habite
• j’écoute

It is the present tense of the verb attacher.

Here it means something like:

• I attach
• I am attaching
• I attach/put on in a habitual sense

French present tense often covers both the simple present and the English present progressive, depending on context.

Avant means before.

In avant la promenade, it is followed directly by a noun phrase:

• avant la promenade = before the walk

French can use avant in different ways:

• avant la promenade = before the walk
• avant de sortir = before going out
• avant que tu partes = before you leave

Here, because promenade is a noun, you simply say avant + noun phrase.

French uses articles much more often than English does. So where English might say before the walk or even just before walking in some contexts, French naturally says avant la promenade if referring to a specific walk or the usual walk.

The article la is there because promenade is:

• feminine
• singular

So its definite article is la.

Yes, médaille literally means medal, but in everyday French it can also mean an ID tag or pet tag, especially on a collar.

So in this context, la médaille is very naturally understood as the tag attached to the dog’s collar.

This is a good example of a word whose most literal English equivalent is not always the best context-based translation.

Because à + le contracts to au in French.

So:

• à le collier → au collier

This contraction is required.

Other common contractions are:

• à + les → aux
• de + le → du
• de + les → des

Since collier is masculine singular and takes le, à le collier becomes au collier.

French often uses attacher quelque chose à quelque chose for to attach something to something.

So the pattern is:

• attacher X à Y
• attach X to Y

Here:

• la médaille = the thing being attached
• au collier = to the collar

That is why à appears.

De la chienne means of the female dog or the female dog’s.

It shows possession or relationship:

• le collier de la chienne = the female dog’s collar

French usually expresses possession with de rather than an apostrophe ’s.

So instead of the dog’s collar, French says:

• the collar of the dog
• le collier du chien
• le collier de la chienne

Here, chienne specifically means a female dog.

Because chienne is the feminine form of chien.

• chien = male dog, or dog in a general sense
• chienne = female dog

So the sentence specifically tells you the dog is female.

Also notice the article changes with gender:

• le chien
• la chienne

Because French keeps the same basic structure as the verb pattern attacher quelque chose à quelque chose:

• j’attache = I attach
• la médaille = the direct object
• au collier de la chienne = where/to what it is attached

So the sentence is built like this:

• Avant la promenade = time expression
• j’attache = verb
• la médaille = thing attached
• au collier de la chienne = to the female dog’s collar

This order is very natural in French.

Sometimes sur can appear in related contexts, but with attacher, the normal pattern is attacher quelque chose à quelque chose.

So:

• attacher la médaille au collier = the standard way to say attach the tag to the collar

Using sur would focus more on physical position on something rather than the act of fastening one thing to another.

A careful pronunciation would be approximately:

Ah-vahn la proh-meh-nad, zha-tash la may-dye oh koh-lyay duh la shee-en.

A few useful notes:

• Avant: the an is nasal
• j’attache: the j’ sounds like the s in measure
• médaille: sounds roughly like may-dye
• au: sounds like oh
• collier: roughly koh-lyay
• chienne: roughly shee-en, with a soft sh sound at the start

The comma is optional but very natural here.

Avant la promenade is a time expression placed at the beginning of the sentence, so a comma helps separate it from the main clause:

• Avant la promenade, j’attache...

It works a lot like English:

• Before the walk, I attach...

Without the comma, the sentence would still be understandable, but the comma makes it easier to read.