(The "e" in the stem changes to "i". This usually applies to verbs ending in -ir.)
Always ensure the verb ending matches the person performing the action. p137 estructura 2 actividades practice it
They used to go to the park every Sunday. (The "e" in the stem changes to "i"
Siempre (always), mientras (while), muchas veces (many times). 3. Watch for Irregulars p137 estructura 2 actividades practice it