Learn Hardcore Spanish (Latin America): El horario es clave para no llegar tarde. - The schedule is key to not arriving late.

In Spanish, when talking about something in general or something specific that both speaker and listener know about, you usually use the definite article el/la. Here, el horario means “the schedule.” Omitting the article (saying just horario) would sound odd—Spanish prefers the article with abstract or general nouns in this kind of sentence.

What does horario mean in this context? Is it “hours,” “timetable,” or “schedule”?

Here, horario most closely means schedule or timetable—i.e., the plan of times you need to follow (for work, school, appointments). It’s not the word for “opening hours” on a shop door (that’s also horario, but context makes it clear). In everyday Latin American Spanish:

horario de clases → class schedule
horario de trabajo → work schedule

What does es clave mean? Why isn’t there an article before clave?

Es clave literally means “is key,” as in “is essential.” In Spanish, when you use a noun as a predicate adjective (to describe something abstract), you normally drop any article. Compare:

Es importante → It’s important
Es esencial → It’s essential
So es clave follows the same pattern, with clave functioning like an adjective (meaning “key” or “crucial”).

Could I say es una clave instead of es clave?

Grammatically, you could say “es una clave”, but it shifts clave back into a concrete noun (“a key,” metaphorically). It’s less common when describing general importance. Saying “es clave” is more idiomatic to mean “it’s crucial.”

Could I replace clave with importante?

Yes. Importante and clave both convey significance, but there’s a nuance:

importante = important (broad, general)
clave = key (stronger, implies “absolutely essential”)
So El horario es importante para no llegar tarde is correct, but es clave feels a bit stronger.

Why is para used before no llegar tarde? What’s its function?

Para introduces a purpose or goal. The structure para + infinitive means “in order to ….” With the negative, para no + infinitive means “so as not to ….” So here:

para no llegar tarde = in order not to arrive/be late

Why is llegar in the infinitive form?

After a preposition (like para), Spanish verbs must stay in the infinitive form. You never conjugate the verb or add que:

Correct: para llegar, sin comer, antes de salir
Incorrect: para llega, sin coman, antes que salgo

Why is no placed before llegar? Could I use nunca instead?

To negate an infinitive after para, Spanish uses no + infinitive. If you used nunca, you’d change the nuance to “never”:

para no llegar tarde = so as not to arrive late
para nunca llegar tarde = so as to never arrive late (stronger, implies “at no time”)
Both are grammatically OK, but para no llegar tarde is more neutral.

Could I say El horario es la clave para no llegar tarde by adding la before clave?

Yes, you can! That turns clave into a concrete noun “the key”:

El horario es la clave → “The schedule is the key (factor) to not being late.”
Both versions are correct:
• es clave (adjective use, idiomatic)
• es la clave (noun use, more metaphorical)