Learn Hardcore Dutch: Na het werk ben ik enorm moe. - After work I am extremely tired.

Bare na werk is technically possible but sounds incomplete or odd in most everyday contexts. Native speakers will normally use het or a possessive like mijn here. So na het werk is the natural default.

Can I say na mijn werk instead of na het werk? Is there a difference?

Yes, you can say:

Na mijn werk ben ik enorm moe.

Both are correct but have a small nuance difference:

Na het werk – more general; can mean “after work” in a routine/habit sense, without focusing on whose work it is. It can still refer to your job in context.
Na mijn werk – clearly refers to your own workday, “after my work.”

In everyday conversation about yourself, both are very normal. Na mijn werk can feel a bit more personal or specific; na het werk a bit more neutral or generic.

Why is it ben ik and not ik ben after Na het werk?

This is the Dutch verb-second (V2) rule:

In a main clause, the finite verb (here ben) must be in the second position.
If you start the sentence with something other than the subject (here: Na het werk = a time phrase), that whole phrase counts as position 1, so the verb must come next.

Structure:

Position 1: Na het werk
Position 2: ben (verb)
Rest: ik enorm moe

So:

Na het werk ben ik enorm moe. ✅
Na het werk ik ben enorm moe. ❌ (verb is not in second position)

Could I also say Ik ben na het werk enorm moe? Is that still correct?

Yes, that is also correct:

Ik ben na het werk enorm moe.

Differences:

Na het werk ben ik enorm moe. – Emphasizes the time: After work, I’m very tired (maybe not at other times).
Ik ben na het werk enorm moe. – Slightly more neutral order; focus is on me being tired, with the time phrase tucked inside.

Both sentences are natural. Dutch allows you to move time and place phrases around as long as you respect the V2 rule (finite verb in second position):

Na het werk ben ik enorm moe.
Ik ben na het werk enorm moe.
Ik ben enorm moe na het werk. (also possible, a bit more spoken-style)

Why is the verb ben and not bent or is?

The verb zijn (to be) is irregular. Present tense:

ik ben – I am
jij/je bent – you are (singular, informal)
hij/zij/het is – he/she/it is
wij/jullie/zij zijn – we/you/they are

Since the subject is ik, you must use ben:

Na het werk ben ik enorm moe.

Using bent or is here would be a conjugation error:

Na het werk bent ik enorm moe. ❌
Na het werk is ik enorm moe. ❌

Is enorm moe natural here, or should I say erg moe or heel moe?

Enorm moe is natural and common in informal speech. It means you are very / extremely tired, with a bit of emphasis.

Some frequent alternatives (all natural):

erg moe – very tired
heel moe – very tired
ontzettend moe – terribly/awfully tired
supermoe – super tired (very informal/colloquial)

Nuance:

erg / heel moe – neutral, suitable in almost any context.
enorm / ontzettend moe – stronger, more expressive.
supermoe – very casual, spoken language.

Your sentence with enorm moe sounds perfectly idiomatic and informal.

Where can I put enorm in the sentence? Does the word order matter?

In this short sentence, enorm should stay right before moe. Correct options include:

Na het werk ben ik enorm moe.
Ik ben na het werk enorm moe.
Ik ben enorm moe na het werk.

You normally don’t split enorm from moe here:

Na het werk ben ik moe enorm. ❌ (unnatural)
Na het werk enorm ben ik moe. ❌

General idea: enorm modifies moe, so it stays immediately before it.

Do I need a comma after Na het werk in Dutch writing?

No comma is needed and it’s normally not written:

Na het werk ben ik enorm moe. ✅

In English, many people write: After work, I am really tired.
In Dutch, you usually do not put a comma between an initial time phrase and the main clause unless the sentence is long or complicated. Here it’s short and simple, so no comma.

Is werk always het werk? Why not de werk?

Yes, werk (work) is a het-word (neuter noun):

het werk – the work
mijn werk – my work
veel werk – a lot of work (no article here)

So you must say:

na het werk ✅
na de werk ❌

The gender (and thus the article) is simply something you have to memorize for each noun. For werk, it is always het in standard Dutch.

What exactly does the preposition na express here? How is it different from op or bij?

Na means after (in time):

na het werk – after work (after the workday ends)

Compare:

op het werk – at work (location: at your workplace)
bij het werk – by/near the work, or “in connection with the work” (context-dependent)
in het werk – in the work (inside the content of some work, e.g. a book, a project)

In your sentence you are talking about time (what happens when work is finished), so na het werk is the correct preposition.

Does this sentence describe a habit, or just one specific day?

By itself, Na het werk ben ik enorm moe. normally sounds like a general/habitual statement: this is how you usually feel after work.

If you want to describe one specific finished day in the past, you’d typically use past tense:

Na het werk was ik enorm moe. – After work, I was really tired (yesterday / that day).

So:

ben → describes your typical situation, or something generally true now.
was → describes a specific moment or period in the past.

Can I drop the ik and say Na het werk ben enorm moe?

No, you cannot drop the subject pronoun in Dutch. You must say:

Na het werk ben ik enorm moe. ✅

Dutch is not a “pro-drop” language like Spanish or Italian. The subject pronoun (ik, jij, hij, etc.) is almost always required, except in imperatives (commands) like:

Kom hier! – Come here!

Is this sentence formal or informal? Would I say this at work?

The sentence itself is neutral; you can use it in both informal and relatively formal contexts.

With colleagues or friends: perfectly fine.
In a very formal written report, you might avoid intensifiers like enorm and choose something slightly more neutral such as erg or just moe, but even enorm moe is still acceptable in most everyday work conversations.

So yes, you can naturally say Na het werk ben ik enorm moe to a colleague in a casual chat.