Confusion when comparing with the other lessons on imperfecto.

Question

So this lesson explains that imperfecto can be thought of as currently happening, while the indefinito is something that happened in the past. But then in the lesson that compares the two with "time markers" it says the opposite. Imperfect is meant to indicate something "used to" happen. Seems like a contradiction. Actually the more I try to understand this topic the more it seems like the type of thing I should just try to memorize first, and then try to wrap my head around it much later.

Accepted Answer

Hola Tanner 
Both tenses are used for past actions but they are used with different nuances: the Indefinido is used for actions the speaker sees as completed actions (sometimes also as simply very punctual actions in the past) and the Imperfecto is used for actions that we are saying "used to happen" (as in habitual actions) for example in "Yo iba mucho a la piscina cuando era pequeña" (I used to go...) or in other contexts the imperfect is a "descriptive" past, as in "Había muchos niños en el parque, hacía mucho calor". Another nuance of the imperfect is "continuity in the past" so we have sentences like "La abuela cocinaba y la niña cantaba" (The grandma was cooking and the girl was singing.) 
Having time phrases in the sentences helps seeing what the tense conveys but if there aren't time phrases it is difficult to see clearly what the speaker is conveying as in English you will generally find only one tense for this.
I hope this clarifies it a bit more.
Saludos
Inma

Answer

Remember both the Indefinido and the imperfect are past tenses. I think you meant to say the imperfect is used to describe what was happening/usually happened in the past.