Has cregut que jo no conec aquesta cançó?

In Catalan, has is the 2nd person singular form of the auxiliary verb haver in the present tense.

So:

• jo he = I have
• tu has = you have
• ell/ella ha = he/she has

That means has cregut literally corresponds to you have believed / thought.

This often surprises English speakers because Catalan has looks exactly like English has, but it does not mean the same person.

Has cregut is the present perfect in Catalan:
haver + past participle

Here:

• has = auxiliary
• cregut = past participle of creure

So the structure is parallel to English have/has + believed/thought.

However, usage does not always match English perfectly. Depending on context, Catalan has cregut can sound like:

• Have you thought... ?
• Did you think... ?

The exact English translation depends on the situation.

Because the verb is creure and its past participle is cregut.

Some common forms of creure are:

• infinitive: creure
• present: crec, creus, creu, etc.
• participle: cregut

So has cregut = you have believed / thought.

This is just an irregular participle pattern you need to learn as part of the verb.

Que introduces the clause jo no conec aquesta cançó.

It works like English that in a sentence such as:

• Have you thought that I don’t know this song?

In English, that is often omitted. In Catalan, after a verb like creure, que is normally kept:

• Crec que... = I think that...
• Has cregut que... ? = Have you thought that... ?

So que is very natural and expected here.

That’s right: Catalan often does drop subject pronouns because the verb ending already shows who the subject is.

So you could say:

• Has cregut que no conec aquesta cançó?

That would still be grammatical.

But adding jo gives emphasis or contrast:

• Has cregut que jo no conec aquesta cançó?

This sounds more like:

• Did you think that I don’t know this song?
• Did you really think I don’t know this song?

So jo is there for emphasis, not because it is required.

Because Catalan distinguishes between conèixer and saber, much like Spanish does.

• conèixer = to know, be familiar with
• saber = to know a fact, know how to, know information

So:

• Conec aquesta cançó = I know this song / I’m familiar with this song
• Sé la resposta = I know the answer
• Sé cantar-la = I know how to sing it

With cançó, conec is very natural if the meaning is I know this song / I’m familiar with it.

Conec is the 1st person singular present tense of conèixer:

• jo conec = I know
• tu coneixes = you know
• ell/ella coneix = he/she knows

So jo no conec aquesta cançó means I do not know this song.

A useful thing to notice is that the verb ending already tells you the subject, which is another reason jo can often be omitted.

In Catalan, no usually goes before the conjugated verb.

So:

• conec = I know
• no conec = I do not know

That is why the sentence says:

• jo no conec aquesta cançó

not:

• jo conec no aquesta cançó

This is very similar to Spanish and simpler than English do-support. Catalan does not need an extra verb like do.

Aquesta means this and it agrees with the noun it modifies.

Cançó is feminine singular, so the demonstrative is also feminine singular:

• aquest = this, masculine singular
• aquesta = this, feminine singular
• aquests = these, masculine plural
• aquestes = these, feminine plural

So:

• aquesta cançó = this song

The form tells you both gender and number.

In this sentence, the easiest clue is the demonstrative:

• aquesta cançó

Since aquesta is feminine singular, the noun must be feminine singular too.

So:

• la cançó = the song
• aquesta cançó = this song

Even though cançó ends in -ó, it is feminine. Word endings can help, but they are not always enough on their own, so determiners like la and aquesta are often your best clue.

In cançó, the ç is called ce trencada and it represents an s sound.

So cançó is pronounced approximately like kan-SO.

A few helpful points:

• ç sounds like s
• the final ó has stress, so the last syllable is stressed
• the written accent helps show that stress

So the stress is on the end:

• can-ÇÓ

Because Catalan does not usually form yes/no questions by changing the word order the way English does.

English:

• Have you thought...?
• Do you know...?

Catalan often keeps the same basic order as a statement and signals the question through:

• intonation
• question marks
• sometimes context

So:

• Has cregut que jo no conec aquesta cançó?

has normal Catalan word order for a question.

Yes. Creure can cover both ideas, depending on context.

It can mean:

• to believe
• to think
• to suppose

So Has cregut que... ? might be understood as:

• Have you believed that... ?
• Did you think that... ?
• Did you suppose that... ?

In many everyday cases, English will prefer think even when Catalan uses creure.

Not always. It is grammatical, but depending on context, many speakers might also use another past form such as:

• Vas creure que jo no coneixia aquesta cançó?
• Has pensat que jo no conec aquesta cançó?

The choice depends on nuance and time reference.

For example:

• has cregut can feel connected to the present
• vas creure is often a straightforward past event
• pensar may sound more like to think
• creure may sound a bit more like to believe / assume

So the given sentence is correct, but it is not the only natural option.