Het baasje praat alsof de hond al zindelijk is.

Baasje is the diminutive of baas. With pets, it usually means the owner, master, or the person the animal belongs to, often in a warm, everyday, affectionate way.

So here het baasje is basically the dog’s owner.

Because baasje is a diminutive, and Dutch diminutives are always het words.

So:

• de baas
• het baasje

This is a very useful rule:

• de hond → het hondje
• de kat → het katje
• de man → het mannetje

Even if the original noun takes de, the diminutive takes het.

Praat is the present-tense singular form of praten, meaning to talk.

Because het baasje is a singular subject, the verb is singular too:

• ik praat
• jij praat
• hij/zij/het praat

So Het baasje praat means The owner talks.

Both can often be translated as to speak/talk, but praten is usually more natural for ordinary, conversational talking.

• praten = talk, chat, speak in an everyday way
• spreken = speak, often a bit more neutral, formal, or focused on the act/language itself

So Het baasje praat alsof... sounds very natural here.

Alsof means as if or as though.

It introduces a subordinate clause:

• Het baasje praat = main clause
• alsof de hond al zindelijk is = subordinate clause

A useful nuance: alsof often suggests that something only seems true, or that the speaker is acting as though it were true, whether or not it really is.

Because after alsof, Dutch uses subordinate-clause word order, and in a subordinate clause the finite verb typically goes to the end.

Compare:

• main clause: De hond is al zindelijk.
• subordinate clause: alsof de hond al zindelijk is

That final verb position is one of the most important word-order patterns in Dutch.

Zindelijk can mean clean or tidy in a general sense, but with children and animals it usually means toilet-trained or house-trained.

So with de hond, the natural meaning is house-trained.

You will also see it in phrases like:

• zindelijk zijn = to be toilet-trained / house-trained
• zindelijk maken = to toilet-train / house-train

Because this adjective comes after is and describes the subject, so it is being used predicatively. Predicative adjectives in Dutch normally do not take -e.

So:

• De hond is zindelijk.
• Het kind is moe.
• De kamer is schoon.

When an adjective comes directly before a noun, it often does take -e:

• een zindelijke hond

But after zijn, the basic form is used: zindelijk.

Al here means already.

So the idea is that the owner is talking as if the dog is already house-trained.

In the subordinate clause, al comes before the adjective:

• de hond al zindelijk is

That is normal Dutch word order.

Yes, it is completely normal Dutch.

English often uses a past or subjunctive form after as if to show unreality or distance, such as were. Dutch usually does not need that same pattern. It normally just uses the ordinary tense that fits the meaning.

So for a present situation, alsof de hond al zindelijk is is the natural choice.

A past form like was could appear in other contexts, but it would usually change the time frame or nuance, not simply copy English were.

Because hond is a de-word in Dutch. Noun gender/article has to be learned with the noun:

• de hond
• de kat
• het paard

So here de hond is simply the correct article for hond.

If you made it a diminutive, it would become het hondje, because diminutives always take het.

In modern Dutch, no comma is needed here, and Het baasje praat alsof de hond al zindelijk is. looks perfectly normal.

Dutch uses fewer commas than English in many cases, especially before subordinate clauses that come after the main clause. A comma could sometimes be added for style or pause, but in this sentence leaving it out is the standard, natural choice.