במקום שנקנה אופנה מהירה, נבחר אופנה בת קיימא.

Here במקום means instead of.

Literally, במקום is something like in place of, but in sentences like this it often works just like English instead of:

• במקום שנקנה... = instead of buying...
• במקום ללכת... = instead of going...

So the sentence sets up a contrast: instead of X, let’s do Y.

The ש־ is a very common Hebrew connector, often meaning that, which, or introducing a clause.

Here, במקום ש־... introduces a full clause:

• במקום שנקנה = literally, instead of that we buy
• more naturally: instead of buying / instead of us buying

A very common alternative would be:

• במקום לקנות אופנה מהירה, נבחר אופנה בת קיימא.

That version uses the infinitive לקנות (to buy) and may feel simpler to learners.

נקנה is the 1st person plural future form of לקנות (to buy):

• אני אקנה = I will buy
• אנחנו נקנה = we will buy

So שנקנה literally means that we will buy or simply that we buy, depending on context.

In this sentence, it does not sound like a plain future event. Because it comes after במקום, it means something more like:

• instead of buying
• instead of us buying

Also, without vowel marks, נקנה can look ambiguous to learners, but here the meaning is clearly the future form of לקנות.

נבחר is the 1st person plural future of לבחור (to choose):

• אני אבחר = I will choose
• אנחנו נבחר = we will choose

But in Hebrew, the 1st person plural future is very often used like English let’s:

• נלך = let’s go
• נעשה = let’s do
• נבחר = let’s choose

So in this sentence, נבחר אופנה בת קיימא is best understood as:

• let’s choose sustainable fashion

not just we will choose sustainable fashion.

Because את is usually used before a definite direct object.

Here אופנה means fashion in a general, non-specific sense, so it is indefinite:

• נקנה אופנה מהירה = buy fast fashion
• נבחר אופנה בת קיימא = choose sustainable fashion

No את is needed.

Compare:

• נבחר אופנה בת קיימא = we’ll choose sustainable fashion
• נבחר את האופנה הזאת = we’ll choose this fashion

In the second sentence, האופנה הזאת is definite, so את appears.

Because אופנה is a feminine singular noun, and the adjective has to agree with it.

So:

• אופנה = feminine singular
• מהירה = feminine singular form of fast

That is why you get:

• אופנה מהירה = fast fashion

If the noun were masculine singular, the adjective would usually be masculine singular instead.

בת קיימא is a set expression meaning sustainable, viable, or able to last.

So:

• אופנה בת קיימא = sustainable fashion

This is not just the ordinary adjective קיימת, which usually means existing.
So בת קיימא is the correct phrase here if you mean environmental or long-term sustainability.

It is best learned as a chunk:

• בת קיימא = sustainable / viable

You may also see it in other contexts, not only with fashion.

Yes — absolutely.

A very natural alternative is:

• במקום לקנות אופנה מהירה, נבחר אופנה בת קיימא.

This version uses the infinitive לקנות (to buy) instead of שנקנה.

Both are grammatical, but they feel slightly different:

• במקום לקנות... = instead of buying...
• במקום שנקנה... = instead of our buying... / instead of us buying...

For many learners, the infinitive version may feel more straightforward.

Hebrew often puts the contrasting idea first for emphasis:

• במקום שנקנה אופנה מהירה, נבחר אופנה בת קיימא.

This structure highlights the choice very clearly:

1. don’t do this
2. do that instead

It is a very natural way to make recommendations, especially in persuasive or formal language.

A simple transliteration is:

Bimkom she-nikne ofna mehira, nivchar ofna bat kayama.

Word by word:

• במקום = bimkom
• שנקנה = she-nikne
• אופנה = ofna
• מהירה = mehira
• נבחר = nivchar
• בת קיימא = bat kayama

If you want, you can think of the rhythm as:

bimKOM sheNIKne OFna mehiRA, nivCHAR OFna bat kaYAma