Swapping present-tense endings to form the preterite

When this student thinks about how to form –ar verbs in the preterite, she uses the present forms of yo and él / ella as a base.  Here’s what she does She visualizes a column with the verb forms in present (e.g., (yo tengo, él tiene).  Next to these, she sees in her mind another column with the preterite forms for yo and él / ella. She switches the present tense yo form’s final –o to the él / ella preterite and the present él / ella form’s final –e to the yo form for preterite.  She indicates the switches by means of arrows. Watch the video clip to see how the student makes this strategy work for her.