How to interpret these sentences in Pretérito indefinido & Pretérito imperfecto?

Question

I've been reading about the differences between the two tenses. It is my understanding that Indefinido is generally for finished things in specified past, while Imperfecto may describe spans of time that might or might not be terminated, or for frequent events.

However, as I spoke with a (non-native but proficient) speaker of Spanish, they interpreted these sentences differently than I'd expect them to:

No conocí la canción. – I still don't know it

No conocía la canción. – I know it now

My guess would be the opposite. How to interpret that difference?

Answer 1

In order to understand your examples some context would be useful, but let's see:

No conocí la canción.

This looks like it's missing something, like a subordinate expression, for example:

No conocí la canción hasta que tuve 40 años.
= "I didn't (get to) know the song until I turned 40 years old."

In this case it's plain that you do know the song now.

No conocí la canción cuando salió.
= "I didn't (get to) know the song when it was released."

In this other case it's a matter of context. With no further information, your hearer would probably ask: "Well, do you know it now?".

Alternatively, conocer can sometimes stand for reconocer "to recognize". If so, it would be as the speaker you consulted said:

No reconocí la canción.
= "(I heard the song but) I didn't recognize the song."

As for the verb in pretérito imperfecto:

No conocía la canción.

Since the imperfect refers to an unfinished process or a non-final state, this strongly implies that you do know the song now. But it's only an implication. If you are narrating a story in the past that mentions the song, this is what you'd say. For example:

Ella quería que cantáramos juntos, pero yo no conocía la canción. Ella se aburrió y se fue. Nunca la volví a ver.

Here you have just stated that you didn't know the song at the time that the story took place. Unless you give the hearer a clue, or flat out tell them that you looked up the song after the incident, it's unknown.

Answer 2

you are talking about the difference between copreterito and preterito

both are two forms to talk in the past tense, while preterito is the purest form of the past tense, the copreterito is the definition of things that "were performed in the past that might or might not have finished" that's why it is considered the "undefined" past tense.

the copreterito verbs are caraterized for finishing in "ia" or "aba".

there are no copreterito verbs in english, there are two translations from Spanish to English, the first one is transform it into the "used to" the second is to transform it into past as infinitive or undefined

"yo compre comida" this means: I bought food, past tense

"yo compraba comida" this means "i used to buy food" or can mean "I was buying food".

depending on the context you might use one form or the other.

this tense is very similar to the "post-preterito" tense, that is the tense when you say something you "would" do if things were different, Example :

"yo compraria un auto, si fuera rico" means: "i would buy a car if i were rich".

This in english we conjugate the verb "buy" with "would" to create the "post-preterito" verb, in spanish we just add an "ria" to the end of the verb