he comido vs comí: choosing the right past for the right time frame
Spanish (in Spain) splits the past by time frame: if the period includes NOW (hoy, esta semana, este año), use the pretérito perfecto; if it is closed (ayer, el lunes, en 2019), use the indefinido.
Hoy he desayunado churros. (Today I had churros — today is still running.)
Ayer desayuné tostadas. (Yesterday I had toast — yesterday is closed.)
English speakers over-use the indefinido. Listen for the time marker — it decides for you.
Present of haber + past participle. Same irregular participles as the pluscuamperfecto.
he · has · ha · hemos · habéis · han + hablado/comido/vivido
¿Has visto mi móvil? (Have you seen my phone?)
Todavía no hemos terminado. (We haven't finished yet.)
Like English "have done" — but remember nothing can separate haber and the participle.
These markers call for the perfecto because the period is still open.
hoy · esta mañana/semana · este mes/año · últimamente (lately)
ya (already) · todavía no (not yet) · alguna vez (ever) · nunca
¿Has estado alguna vez en México? (Have you ever been to Mexico?)
Experience questions (¿alguna vez...?) always take the perfecto — just like English "have you ever...?".
These markers close the period and demand the indefinido.
ayer · anoche · la semana pasada · el año pasado · en 2015 · hace dos días
Anoche cené con mis padres. (Last night I had dinner with my parents.)
En 2019 viajamos a Chile. (In 2019 we travelled to Chile.)
Unlike British English, Spanish is strict: "hoy" really does force the perfecto, "ayer" really does force the indefinido.
In most of Latin America the indefinido covers nearly everything ("Hoy desayuné churros" is normal in Mexico). This course teaches the Castilian distinction — examiners expect it, and you will understand both.
Spain: Hoy he comido paella. · Mexico: Hoy comí tacos.
Both are correct Spanish — but match your register to your exam.
Exam tip: in writing, pick one system and stay consistent throughout your text.
Traps for English speakers
These are the errors English speakers make most often.