The tense in which hacer is conjugated affects the entire meaning of the sentence and influences whether the imperfect or preterite tense is appropriate for the other verb in the sentence. Hace formulas are used in Spanish to indicate how long something happened, or how long ago something had been happening.
Hace formula sentences are called “idiomatic” because they use a specific formula of verbs and tenses to create a meaning that is not exactly word for word the way the sentence is written in English. Pay close attention to the examples for each formula because the English sentences are written very differently. In some cases, a literal translation of the Spanish sentence is included in parentheses just to show how strange these sentences would sound if translated word for word to English.
The question created in the following formula is used to ask how long ago something occurred:
Question structure formula: Cuánto tiempo hace + que + preterite
¿Cuánto tiempo hace que conociste a Berto?
How long ago did you meet Berto?
The formula used to state how long ago something occurred is similar to the formula used to ask the question. The verb following que is in the preterite tense because it happened at a specific time. This idiomatic expression indicates how long ago the verb in the preterite was done.
Sentence structure formula: Hace + time + que + preterite
Hace dos años que conocí a Berto.
I met Berto two years ago. (It “makes” two years that I met Berto.)
Hace un mes que Carmen llegó.
Carmen arrived a month ago. (It “makes” a month that Carmen arrived.)
To ask a question about how long something had been going on, use the following question formula:
Question structure formula: ¿Cuánto tiempo hacía que + imperfect?
¿Cuánto tiempo hacía que tú y Mario trabajaban juntos?
How long had you and Mario been working together?
When hacer is used in the imperfect with an amount of time, que, and another verb in the imperfect tense, this expression indicates how long something had been going on in the past and that continued in the past until something else happened. Here is the formula:
Sentence structure formula: Hacía + time + que + imperfect
Hacía una semana que visitaba a mis primos.
I had been visiting my cousins for a week. (It “made” a week that I had been visiting my cousins)
Hacía ochos días que no dormía.
I hadn't been sleeping for eight days. (It “made” eight days that I wasn't sleeping.)
When the imperfect tense is used with desde hace, the expression is the same as the formula with the imperfect and hacía. These sentences indicate how long something had been going on.
Sentence structure formula: imperfect + desde hace + time
Bailaban desde hace una hora.
They had been dancing for an hour (and it is still going on).
The following type of question formula is used to elicit a response using desde hace. Questions using this formula ask how long something had been going on.
Question structure formula: Desde cuándo + imperfect
¿Desde cuándo bailaban?
How long had they been dancing?