Jag följde hennes råd i går, och i dag känner jag mig faktiskt piggare.

Följde is the past tense of följa, meaning to follow. In this sentence, it tells you the action happened yesterday.

Useful forms:

• följa = to follow
• följer = follow / is following
• följde = followed
• följt = followed, in forms like har följt

So Jag följde hennes råd means I followed her advice.

Swedish uses sin/sitt/sina only when the possessor is the same as the subject of the clause.

Here, the subject is jag = I, but the advice belongs to her, so Swedish uses hennes.

• Jag följde hennes råd = I followed her advice
• Hon följde sitt råd would mean she followed her own advice

So hennes is correct because the advice belongs to someone other than the subject.

Råd can be a little tricky because the indefinite singular and indefinite plural look the same.

• ett råd = a piece of advice / a tip
• flera råd = several pieces of advice / several tips

In hennes råd, the form itself does not tell you whether it is singular or plural. The context does. Very often, it is understood as her advice in a general sense.

Also, after a possessive like hennes, Swedish does not use an article:

• hennes råd not
• hennes ett råd

These are traditional spellings of Swedish time expressions:

• i går = yesterday
• i dag = today

You will also often see igår and idag, especially in less formal writing. Both spellings are common and accepted, but i går and i dag are often preferred in careful or traditional writing.

So here the spacing is completely normal.

This is because Swedish main clauses follow the V2 rule, which means the finite verb normally comes in the second position.

If you start the clause with something other than the subject, such as a time expression, the verb still stays second, and the subject comes after it.

So:

• Jag känner mig piggare i dag = subject first
• I dag känner jag mig piggare = time expression first, so verb comes before the subject

That is why the sentence says och i dag känner jag mig...

Because Swedish often uses the reflexive expression känna sig to mean to feel in the sense of being in a certain state.

• Jag känner mig piggare = I feel more energetic / I feel better
• literally, something like I feel myself more energetic

Without mig, känner jag would usually mean I know, I recognize, or I feel something else.

So in this sentence:

• känner jag mig = I feel

Piggare is the normal comparative form of pigg.

• pigg = energetic, alert
• piggare = more energetic, more alert

Many short Swedish adjectives form the comparative with -are:

• snabb → snabbare
• billig → billigare
• pigg → piggare

Using mer pigg is not the normal choice here. Piggare is the natural Swedish comparative.

Faktiskt adds emphasis. Here it suggests something like:

• actually
• really
• in fact

In this sentence, it gives a slight nuance of pleasant surprise or confirmation: I do actually feel more energetic today.

It makes the statement sound a bit more personal and a bit less flat.

Because the sentence talks about two different times:

• i går = yesterday, so följde is past tense
• i dag = today, so känner is present tense

This is completely normal in Swedish. The speaker is saying:

1. Yesterday, I followed her advice.
2. Today, I feel more energetic.

So the tense changes because the time frame changes.

Not always. Swedish punctuation is a bit more flexible here than many learners expect.

A comma before och can be used when two full clauses are joined, especially if the writer wants a clearer pause:

• Jag följde hennes råd i går, och i dag känner jag mig faktiskt piggare.

Many writers would also write it without the comma:

• Jag följde hennes råd i går och i dag känner jag mig faktiskt piggare.

So the comma is acceptable, but not absolutely required.

Yes, very natural. Följa någons råd is the normal way to say follow someone’s advice.

For example:

• Hon följde läkarens råd = She followed the doctor’s advice
• Du borde följa hans råd = You should follow his advice

So Jag följde hennes råd is idiomatic Swedish.

No. Swedish verbs do not change for person.

So the same present-tense form is used with all subjects:

• jag följer
• du följer
• hon följer
• vi följer

That makes Swedish simpler than English in this area. In your sentence, följde would stay följde no matter who the subject was:

• Jag följde
• Hon följde
• Vi följde