Answer: Spanish verbs that end in -GAR must change the g to a gu before adding the ending of "yo" form in the preterite tense.
Examples:
"Regar" goes to "yo regué"
"Rogar" goes to "yo rogué"
"Vagar" goes to "yo vagué"
"Tragar" goes to "yo tragué"
"Fregar" goes to "yo fregué"
Spymore
