Learn Hardcore Spanish (Latin America): No estudié con calma, por eso no comprendo la lección. - I didn't study calmly, that's why I don't understand the lesson.

Con calma is an idiomatic preposition-plus-noun phrase that Spanish speakers commonly use to express “calmly” or “at one’s leisure.” Although calmamente does exist, con calma often sounds more natural in everyday conversation and places a bit more emphasis on the manner in which the action is done.

What does por eso mean, and how does it differ from connectors like por lo tanto or así que?

Por eso means “therefore” or “that’s why”, signaling a cause-and-effect relationship between two clauses.

Por lo tanto is slightly more formal and often found in written or academic Spanish.
Así que is more colloquial and interchangeable with por eso in many contexts, though it can feel a bit more casual.

Why is estudié in the pretérito indefinido instead of the present perfect (e.g., he estudiado)?

In Latin American Spanish, the pretérito indefinido (estudié) is the default past tense for completed actions, regardless of whether you specify a time. The present perfect (he estudiado) is less common in many Latin American varieties and usually reserved for actions that have clear relevance or immediacy in the present. Here, the speaker simply states a finished event: “I didn’t study calmly.”

Why is the second verb comprendo in the present tense instead of a past tense like comprendí?

The sentence expresses a current state: because you didn’t study calmly, you still don’t understand the lesson now. Using comprendo (present) emphasizes that the lack of understanding persists in the present moment. If you said no comprendí, it would mean you didn’t understand it at the time, but you might understand it now.

Why is there a comma before por eso?

In Spanish, when you link two independent clauses with connectors like por eso, sin embargo, or además, it’s standard to place a comma before the connector. It clarifies the pause and shows the logical jump from cause to effect. While not always strictly mandatory, the comma improves readability.

What’s the nuance between comprender and entender in no comprendo la lección?

Both verbs mean “to understand,” but there’s a subtle difference:

Entender often refers to grasping basic or practical meaning.
Comprender can imply a deeper or more complete understanding.
In everyday speech, they’re largely interchangeable: no entiendo la lección would be just as correct here, though it may feel slightly less formal.

Why do we use the definite article la in la lección?

Spanish typically requires definite articles before nouns, especially when the noun is specific and known to both speaker and listener. In this case, la lección refers to a particular lesson you’ve been studying, so the article la is necessary.

Can I replace la lección with a direct-object pronoun?

Yes. Since lección is feminine singular, the pronoun is la. Clitic pronouns in Spanish go before a conjugated verb. The sentence becomes:
No estudié con calma, por eso no la comprendo.