Jag tycker att den gamla bron känns farlig på kvällen.

In Swedish, when a noun is definite and has an adjective before it, you usually use double definiteness:

• den = the
• gamla = old
• bron = the bridge

So den gamla bron literally looks like the old the-bridge, but this is normal Swedish grammar.

Compare:

• en gammal bro = an old bridge
• den gamla bron = the old bridge

This pattern is very common in Swedish.

Bro means bridge. It is a common gender noun (en-word), and its definite singular form is made by adding -n:

• en bro = a bridge
• bron = the bridge

This is a standard way many en-words form the definite singular.

The adjective changes form depending on the noun phrase.

Here are the main forms of gammal:

• en gammal bro = an old bridge
• ett gammalt hus = an old house
• gamla broar = old bridges
• den gamla bron = the old bridge

In definite noun phrases, adjectives usually take the -a form, so den gamla bron is correct.

Because it describes bron, which is an en-word.

Adjective agreement here works like this:

• en bro är farlig = a bridge is dangerous
• ett hus är farligt = a house is dangerous

Since bro is common gender, the adjective stays in the common gender/basic form: farlig.

Tycker comes from tycka, which often means to think, to feel, or to have the opinion that.

In this sentence, Jag tycker att ... means something like:

• I think that ...
• I feel that ...
• In my opinion ...

It introduces the speaker’s personal judgment.

A learner should notice that Swedish often uses tycka att for opinions, especially where English says I think that ...

Att here means that and introduces a subordinate clause.

So the sentence is divided like this:

• Jag tycker = I think
• att den gamla bron känns farlig på kvällen = that the old bridge feels/seems dangerous in the evening

In everyday Swedish, att is sometimes omitted in speech, but including it is completely normal and often clearer.

Because after att, Swedish uses subordinate clause word order.

This clause is straightforward:

• den gamla bron = subject
• känns = verb
• farlig = complement

So:

• att den gamla bron känns farlig = that the old bridge feels/seems dangerous

Nothing unusual has happened here, but it is useful to notice that the clause after att behaves like a full clause with its own subject and verb.

Känns is the passive or middle-style form of känna, and in this kind of sentence it often means:

• feels
• seems
• comes across as

So bron känns farlig is not saying the bridge itself has emotions. It means the bridge gives an impression of being dangerous.

A natural English translation might be:

• the old bridge feels dangerous
• the old bridge seems dangerous

Both capture the idea.

There is an important difference:

• bron är farlig = the bridge is dangerous
  This sounds more factual or objective.

• bron känns farlig = the bridge feels/seems dangerous
  This sounds more subjective, based on impression or experience.

Since the sentence begins with Jag tycker and expresses personal opinion, känns fits very well.

På kvällen means in the evening or during the evening.

Literally:

• på = on
• kvällen = the evening

But in English we translate it as in the evening.

This is a common time expression in Swedish. Compare:

• på morgonen = in the morning
• på dagen = during the day / in the daytime
• på kvällen = in the evening
• på natten = at night / during the night

In many Swedish time expressions, the definite form is used:

• på morgonen
• på eftermiddagen
• på kvällen
• på natten

So even though English often says just in the evening, Swedish commonly uses the definite form: på kvällen.

Not always. Swedish has several ways to express I think:

• Jag tycker att ... = I think / I feel / in my opinion
  Used for opinions and personal judgments.

• Jag tror att ... = I think / I believe
  Used more for belief, assumption, or something you think is true.

In this sentence, Jag tycker att den gamla bron känns farlig sounds natural because it expresses a personal impression.
If you said Jag tror att den gamla bron är farlig, that would sound more like a belief about an actual fact.

Yes. Swedish allows that, but then the finite verb must come second in the main clause.

For example:

• På kvällen tycker jag att den gamla bron känns farlig.

This keeps the normal Swedish V2 pattern: the verb tycker stays in second position.

But inside the subordinate clause after att, the word order does not follow main-clause V2 in the same way.

It is natural and normal Swedish. It sounds like something a person might genuinely say in conversation or writing.

It is neither especially formal nor especially casual. The structure is clear, idiomatic, and useful for learners because it includes several very common patterns:

• Jag tycker att ...
• definite noun phrase with adjective: den gamla bron
• impression with känns
• time phrase: på kvällen