conjugation.preterite.spelling-car-gar-zar
Preterite spelling: -car, -gar, -zar (busqué, llegué, crucé)
In the yo preterite, c → qu, g → gu, z → c before the -é ending: buscar → busqué, llegar → llegué, cruzar → crucé. Pronunciation never changes.
conjugationA2standardinternally_reviewedv1.0.0
Explanation
The yo preterite of -ar verbs ends in -é. To keep the stem's sound in front of that e, spelling adjusts: c would soften, so it becomes qu (busqué); g would soften, so it becomes gu (llegué); and Spanish avoids ze, so z becomes c (crucé).
Only the yo form of the preterite is affected in the indicative — the other persons keep the original letter: buscaste, llegó, cruzamos.
The same adjustment runs through the entire present subjunctive of these verbs, because all its endings start with e: busque, llegues, crucemos. Verbs in -guar add a diaeresis: averiguar → averigüé.
Examples
I looked for the document all morning.
Region: global
I arrived late to the meeting.
Region: global
I crossed the border by bus.
Region: global