Retourneer alleen een compleet product.

Because retourneer is an imperative form: it is used for commands, instructions, or requests.

So:

• Retourneer ... = Return ...
• It is directed at you (singular or plural, depending on context)

This is very common in instructions, notices, and webshop language.

Comparable examples:

• Lees de handleiding. = Read the manual.
• Bewaar de bon. = Keep the receipt.
• Open de verpakking niet. = Do not open the packaging.

In this sentence, the subject you is not stated, because Dutch normally leaves it out in commands.

Retourneer comes from retourneren, which means to return something, especially in a shop, delivery, or customer-service context.

So here it means something like:

• return
• send back
• hand back

It is a fairly formal or commercial word. In everyday speech, Dutch speakers often prefer more natural alternatives like:

• Stuur ... terug = send ... back
• Breng ... terug = bring ... back

So this sentence sounds very suitable for a return policy, a webshop, or packaging instructions.

Alleen means only. Its position shows what it applies to.

In Retourneer alleen een compleet product, alleen limits the action/object combination: you should return only a complete product, not an incomplete one.

Dutch often places alleen before the part it is emphasizing, but in practical instructions this position is very normal.

A learner-friendly way to read it is:

• Retourneer alleen ... = Only return ...
• een compleet product = a complete product

So the sentence means: return something only if it is complete.

Because een is the indefinite article, while het is the definite article.

• het product = the product
• een product = a product

The fact that product is a het-word matters when you use the definite article:

• het product
• het complete product

But in this sentence, the meaning is indefinite/general, so Dutch uses een:

• een compleet product = a complete product

So there is no contradiction here.

This is about adjective endings in Dutch.

In Dutch, adjectives often take -e, but there is one important exception:

When an adjective comes before a singular neuter noun with een, it usually has no -e.

That is exactly what happens here:

• product is a het-word (neuter)
• it is singular
• it has the indefinite article een

So:

• een compleet product ✔
• een complete product ✘

Compare:

• het complete product = the complete product
• een compleet product = a complete product

This is a very common grammar point for learners.

Yes, absolutely. But it means something slightly different.

• een compleet product = a complete product
• het complete product = the complete product

With het, you are talking about a specific product that is already known from the context.

Also notice the adjective ending changes:

• een compleet product
• het complete product

That happens because with het + adjective + noun, the adjective normally takes -e.

Yes, and in many contexts that may even sound more natural.

That version means:

• Return only complete products

It is more general and plural.

Notice the adjective form:

• complete producten

In the plural, adjectives normally take -e, so complete is correct here.

Compare:

• een compleet product = a complete product
• complete producten = complete products

Both are correct; the choice depends on whether the instruction is about one item at a time or products in general.

It is correct and natural in a formal/commercial setting, especially in written instructions.

But in more everyday Dutch, many speakers would say something like:

• Stuur alleen complete producten terug.
• Breng alleen complete producten terug.
• Retourneer alleen complete artikelen.

So retourneer is perfectly fine, but it has a slightly formal/customer-service feel.

Both can mean complete, but there is a slight nuance.

• compleet often means all parts/accessories are included
• volledig can sound a bit more formal and can mean fully complete in a broader sense

In a returns context, compleet is very natural because it suggests that nothing is missing.

For example, a seller may mean:

• the item
• the accessories
• manuals
• packaging
• separate parts

So een compleet product strongly suggests that the whole item must be intact and complete.

A rough English-friendly pronunciation could be:

reh-toor-NEER ah-LAYN un kom-PLAYT pro-DUKT

A few notes:

• retourneer has stress near the end: retourNEER
• alleen sounds like ah-LAYN
• een is usually reduced in normal speech, often sounding like un
• compleet has stress on the second syllable: comPLAYT
• product is usually stressed on the second syllable: proDUKT

The Dutch r and vowels will differ from English, of course, but this approximation can help at first.

Most likely in a context such as:

• a webshop return policy
• a customer-service message
• instructions inside a package
• a returns form
• a warranty condition

It sounds like a rule telling customers not to return items that are incomplete, damaged, or missing parts.

So the practical meaning is something like:

• only send back the item if everything is included
• do not return loose parts or incomplete items