Learn Hardcore French: Après la balade, nous ramassons les coussins sur le canapé. - After the walk, we pick up the cushions on the couch.

English can say: after walk, after dinner, after school
French almost always says: après la balade, après le dîner, après l’école

So balade (a walk / stroll) needs an article: la balade.
Leaving it out (après balade) sounds wrong in standard French.

What’s the nuance of balade? Is it the same as promenade?

Both balade and promenade can mean a walk or stroll, but there are some nuances:

balade: more informal, relaxed
- faire une balade = go for a walk / stroll / ride (even by car or bike)
promenade: a bit more neutral or formal, often just a walk (especially on foot)
- faire une promenade = go for a walk

In everyday speech, faire une balade is very common.
You could also say:

Après la balade
Après la promenade

Both are correct here, just a slightly different feel.

Why is the verb in the present tense (nous ramassons) if it happens after the walk? Shouldn’t it be future?

French often uses the present tense where English uses the future, especially when there is a time expression that makes the sequence clear.

Après la balade, nous ramassons les coussins.
Literally: After the walk, we pick up the cushions.

In English you might expect:

After the walk, we’ll pick up the cushions.

But in French, the time marker après la balade already shows it’s later, so the present tense works fine.

You can use the future:

Après la balade, nous ramasserons les coussins.

This is also correct, but it sounds more like a specific plan or promise. The plain present is very natural in everyday speech.

Why is it les coussins and not des coussins?

les coussins refers to a specific set of cushions that the speaker and listener have in mind, probably the ones that are normally on that sofa.

les coussins = the cushions (those particular ones)
des coussins = some cushions (unspecified, not necessarily known which)

Here, we’re likely talking about the regular cushions on that sofa, so French uses les.

What exactly are coussins? Are they like pillows?

Yes, but there’s a useful distinction:

un coussin: a cushion (often for a sofa, chair, or decoration)
un oreiller: a pillow you sleep on in bed

In English, pillow is sometimes used for both, but in French:

On the sofa: des coussins
On the bed (for sleeping): des oreillers

Why is it sur le canapé and not du canapé?

The preposition changes the meaning:

sur le canapé = on the sofa
- Location: where the cushions are.
du canapé can mean:
- from the sofa (movement away): ramasser les coussins du canapé = pick up the sofa’s cushions (take them off the sofa),
- or of the sofa (possession): les coussins du canapé = the sofa’s cushions.

In the original sentence, the idea is that the cushions are physically on top of the sofa, so sur is the right preposition:

nous ramassons les coussins sur le canapé
= we pick up the cushions that are on the sofa.

Why is canapé masculine (le canapé)?

Gender in French is mostly arbitrary and must be memorised for each noun.

un canapé (masculine) = a sofa
So: le canapé, du canapé, au canapé, etc.

There’s no reliable rule that would tell you canapé must be masculine; you just learn it with its article:

un canapé
le canapé
les canapés (plural)

How is ramassons formed, and what does ramasser literally mean?

ramasser is an -er verb that means to pick up / to gather / to collect.

Present tense (indicative) conjugation:

je ramasse
tu ramasses
il / elle / on ramasse
nous ramassons
vous ramassez
ils / elles ramassent

In the sentence:

nous ramassons = we pick up / we are picking up

So ramasser les coussins = pick up / gather the cushions.

Could I say nous rangeons les coussins instead of nous ramassons les coussins?

You could, but the meaning changes slightly:

ramasser les coussins: pick them up from wherever they are (e.g. scattered on or around the sofa).
ranger les coussins: tidy / put the cushions away in their proper place.

You might:

ramasser them from the floor or sofa, then
les ranger in a cupboard or put them neatly back on the sofa.

In your sentence, ramassons focuses on picking them up.

Can I replace nous with on in this sentence?

Yes:

Après la balade, on ramasse les coussins sur le canapé.

In spoken French, on is extremely common and very often used instead of nous to mean we.

Differences:

nous ramassons: grammatically formal/plural “we pick up”
on ramasse: grammatically “one picks up”, but in everyday French it usually means “we pick up”

So in conversation, on ramasse would sound a bit more natural; in writing, nous ramassons is more standard/neutral.

Why is sur le canapé at the end? Could I move it?

French word order here is quite flexible, but some options sound more natural than others.

Most natural:

Après la balade, nous ramassons les coussins sur le canapé.

Possible, but less usual or more marked:

Après la balade, nous ramassons sur le canapé les coussins. (unusual emphasis)
Après la balade, sur le canapé, nous ramassons les coussins. (emphasises the place, e.g. contrasting with elsewhere)

Keeping les coussins right after the verb and the place phrase sur le canapé at the end is the most neutral and common structure.