Hola,
The third person plural form of the Present tense, (El Presente), and the Preterite tense, (El Preterito Indefinido), are identical for -ar verbs.
Since that is the case, may I suggest that there is a note about this in the lesson with a few examples to show how context can clarify which tense is being used? This would be very helpful.
A simple chart comparing the present and past conjugations alongside each other of some common verbs such as 'trabajar' or 'hablar' would also be useful, especially for those learners who are very visual.
Gracias y Saludos!
