Learn Hardcore Swedish: Jag försöker följa den regeln.

In Jag försöker följa den regeln, it means I am making an effort / I attempt to follow that rule.
It does not mean to try out / to test (like try this cake). For that sense you would more often use prova or testa in Swedish.

Why is följa in this form and not följer?

Följa is the infinitive form of the verb, like English to follow.

After försöker (I try), Swedish normally uses the infinitive form of the next verb:

Jag försöker följa den regeln. – I try to follow that rule.
Han försöker förstå. – He tries to understand.

Using följer here (Jag försöker följer den regeln) would be incorrect, because Swedish does not stack two finite (conjugated) verbs in this way. One is conjugated (försöker), and the next stays in the infinitive (följa).

Can I say Jag försöker att följa den regeln, and does att change the meaning?

Yes, you can say:

Jag försöker följa den regeln.
Jag försöker att följa den regeln.

Both are grammatically correct and mean the same thing for practical purposes: I try to follow that rule.

In modern spoken Swedish, many people omit att after verbs like försöka, börja, sluta, lära sig, etc. Including att can sound a bit more formal or careful, but in everyday speech most people would say Jag försöker följa den regeln without att.

Why is it den regeln and not just regeln?

Both are possible, but there is a nuance:

regeln = the rule (definite form)
den regeln = that rule or that particular rule (often slightly more specific or contrastive)

So:

Jag försöker följa regeln.
– I try to follow the rule (more neutral, just “the rule” everyone knows about).
Jag försöker följa den regeln.
– I try to follow that rule (often implying that one, maybe in contrast to other rules, or one that was just mentioned).

In Swedish, using den + definite noun (den regeln) often emphasizes a specific rule that you and the listener both know about or have just been talking about.

How is regel declined? What are the singular and plural forms?

Regel is an en-word (common gender). Its main forms are:

Indefinite singular: en regel – a rule
Definite singular: regeln – the rule
Indefinite plural: regler – rules
Definite plural: reglerna – the rules

So:

Jag försöker följa den regeln. – I try to follow that rule.
Jag försöker följa de reglerna. – I try to follow those rules.

Is regel an en-word or an ett-word, and how can I tell?

Regel is an en-word (common gender):

en regel – a rule
regeln – the rule

Unfortunately, in Swedish there is no reliable rule to predict whether a noun is en or ett. Learners usually have to:

Memorize the gender together with the word (e.g. en regel)
Notice typical patterns over time (many abstract nouns and people/animals are en, many short concrete things are ett, but there are many exceptions)

For regel, you just have to learn it as en regel.

How would I say I follow that rule instead of I try to follow that rule?

You would conjugate följa instead of försöka:

Jag följer den regeln. – I follow that rule.

Compare:

Jag försöker följa den regeln. – I try to follow that rule.
Jag följer den regeln. – I do follow / I am following that rule.

So försöker adds the meaning of attempt/effort, while följer simply states the fact that you (do) follow the rule.

Where does inte go if I want to say I don’t try to follow that rule?

You put inte after the first finite verb, which here is försöker:

Jag försöker inte följa den regeln.
– I don’t try to follow that rule.

You would not say Jag försöker följa inte den regeln.
The general pattern is: subject – finite verb – inte – (infinitive verb / rest of the sentence).

Why is the verb in second position (after Jag)? Could I move försöker somewhere else like in English?

Swedish main clauses follow the V2 rule (Verb Second):

First position: usually the subject (here Jag)
Second position: the finite verb (here försöker)

So:

Jag försöker följa den regeln. (Subject – Verb – …)

If you move something else to the front, the verb still stays in second position:

I morgon försöker jag följa den regeln.
– Tomorrow I’ll try to follow that rule.

English allows I tomorrow try (in poetry, etc.), but normal English is more flexible with adverbs. Swedish is stricter: in main clauses, the finite verb must remain in second position.

How do I pronounce försöker and regel correctly?

Rough guide (Swedish varies by region, but this is standard-ish):

försöker

för – has the ö sound (like a mix between the e in her and the u in burn, but with rounded lips).
sj-sound in försöker (the s
- k before ö) is a hissy, dark sh-like sound, produced further back in the mouth than English sh.
Stress is on the middle syllable: för-SÖ-ker.

regel

re – like ray but shorter.
gel – like yell but with a y or soft English y/j sound at the start of the syllable.
Stress is on the first syllable: RE-gel.

To get closer, listening to native audio on a dictionary site and repeating is very helpful.

What is the difference between den regeln, den här regeln, and den där regeln?

All three refer to a specific rule, but with different shades:

den regeln – that rule / that particular rule
Often used when the rule is contextually clear or has been mentioned; can sound slightly emphatic or contrastive.
den här regeln – this rule
Literally “this rule (here)”; often something currently being discussed or metaphorically “close”.
den där regeln – that rule (over there / that one)
More clearly “that one (over there / that one we mentioned earlier)”, often a bit more distant or maybe less liked.

In many contexts, den regeln and den där regeln can overlap in meaning (that rule), but den här regeln is clearly this rule.

Could I drop den and just say Jag försöker följa regeln? Does it change the meaning?

Yes, you can say:

Jag försöker följa regeln.

That means I try to follow the rule in a neutral way.

Jag försöker följa den regeln usually adds a bit more specificity or emphasis, like:

I try to follow that particular rule (as opposed to other rules).

Context decides how big the difference feels, but generally:

regeln – the rule (neutral)
den regeln – that specific rule (slightly more pointed/contrastive)

Is this sentence formal, informal, or neutral? Are there more casual alternatives?

Jag försöker följa den regeln. is neutral Swedish. You can use it in writing, in conversation, at work, with friends – it fits almost any context.

More casual or more explicit variants (but similar meaning) could be:

Jag försöker hålla mig till den regeln. – I try to stick to that rule.
Jag försöker faktiskt följa den regeln. – I do actually try to follow that rule.

But the original sentence is perfectly natural and not especially formal or stiff.