De proefplaatsing gaat goed, behalve dat de hond gromt.

Proefplaatsing is a compound noun:

• proef = trial / test
• plaatsing = placement

So proefplaatsing literally means trial placement. In context, it is often used for situations like a foster or trial adoption period, especially with animals, but it can also be used more generally for a temporary placement to see whether something works out.

Dutch forms compound nouns very often, much more freely than English.

Because plaatsing is a de-word, and compounds usually take the gender/article of the last part of the compound.

• de plaatsing
• therefore de proefplaatsing

This is a useful rule in Dutch: for compound nouns, the final element usually determines whether the whole word takes de or het.

Dutch often uses gaan in expressions where English uses to go or sometimes simply to be going well.

• Het gaat goed = It’s going well
• De proefplaatsing gaat goed = The trial placement is going well

So gaan is very natural here.
If you said De proefplaatsing is goed, that would sound more like the placement is good as a general description, not specifically that the process is progressing well.

Because De proefplaatsing itself is the subject.

Compare:

• Het gaat goed. = It is going well.
• De proefplaatsing gaat goed. = The trial placement is going well.

In the second sentence, there is no need for het as a dummy subject, because the real subject is already there: de proefplaatsing.

Behalve dat means except that.

So:

• De proefplaatsing gaat goed, behalve dat de hond gromt.
• The trial placement is going well, except that the dog growls.

This structure is used when one thing is generally true, but there is one exception or problem.

Because dat introduces a subordinate clause, and in Dutch subordinate clauses the conjugated verb usually goes to the end.

Main clause:

• De hond gromt.

Subordinate clause:

• ... dat de hond gromt

This is one of the most important Dutch word-order patterns:

• main clause: verb usually in second position
• subordinate clause: verb goes to the end

Yes, but they mean slightly different things.

• behalve
  • noun
    
    • behalve de hond = except the dog
• behalve dat
  • clause
    
    • behalve dat de hond gromt = except that the dog growls

Here the speaker wants to express a whole idea (the dog growls), not just name a thing, so dat is needed to introduce that full clause.

Gromt is the third-person singular present tense of grommen.

Conjugation:

• ik grom
• jij gromt
• hij/zij/de hond gromt
• infinitive: grommen

It means to growl.

So:

• de hond gromt = the dog growls / is growling

Yes, gromt can feel awkward for English speakers because of the consonant cluster at the end.

A rough guide:

• grom sounds a bit like English khrom or hrom, depending on how strongly the Dutch g is pronounced in the speaker’s accent
• then add a t at the end: gromt

Important points:

• the Dutch g is not like the English g in go
• the o is short
• the final t is pronounced

If it helps, think of it as:

• grom-men → remove -en → grom
• then add -t → gromt

Because behalve dat de hond gromt is an added subordinate clause giving an exception to the main statement.

Dutch punctuation often uses a comma before this kind of clause, especially when it comes after the main clause and adds extra information.

So the sentence naturally splits into:

• De proefplaatsing gaat goed
• behalve dat de hond gromt

Not exactly.

• maar = but
• behalve dat = except that

Both can contrast two ideas, but behalve dat emphasizes that things are generally fine apart from one exception.

Compare:

• De proefplaatsing gaat goed, maar de hond gromt.
  = The trial placement is going well, but the dog growls.
• De proefplaatsing gaat goed, behalve dat de hond gromt.
  = The trial placement is going well, except that the dog growls.

The second version sounds a little more specific: there is basically one notable problem.

Not with exactly the same meaning.

• terwijl = while / whereas
• alhoewel = although
• behalve dat = except that

These are different relationships between clauses.

For example:

• De proefplaatsing gaat goed, alhoewel de hond gromt.
  This is understandable, but it sounds more like although the dog growls.
• De proefplaatsing gaat goed, behalve dat de hond gromt.
  This clearly presents the growling as the main exception.

So behalve dat is the best choice if you mean everything is going fine except for this one issue.

Yes, it is natural and clear.

It sounds like something you might hear in a practical discussion, for example about a dog in a foster home or trial adoption period. The tone is fairly neutral and matter-of-fact.

A few natural alternatives might be:

• De proefplaatsing gaat goed, maar de hond gromt wel.
• De proefplaatsing verloopt goed, behalve dat de hond gromt.
• De proefplaatsing gaat eigenlijk goed; alleen gromt de hond.

But the original sentence is perfectly normal Dutch.