How Do You Say "Ago" in Spanish?
.... you don't!
In Spanish, the verb hacer is used in three ways to show three things:
1. How long something has been going on -- in meaning, present perfect, but not employing this tense in Spanish;
2. How long ago something happened -- a function related to and involving the preterite in Spanish, and;
3. How long something had been going on -- at some undefined time ago in the past -- a function equivalent to, but not employing, the pluperfect in Spanish.
To be absolutely honest, there is no structure of English that will help English-speaking students of Spanish grasp the ways in which Spanish expresses these ideas. It is very important, therefore, to know what the equivalents are to the Spanish structures, which all involve hacer.
By memorizing the following Spanish sentences with their corresponding English meanings, students are able to more quickly arrive at a solution for what they are thinking in English. Here are the Spanish sentences with their English counterparts:
1. Hace una hora que escucho la radio. Present perfect in meaning, as the English renders it: I have been listening to the radio for an hour.
2. Hace dos días que vi a Enrique. This is the way in which Spanish renders what English does with the little word "ago": I saw Henry two days ago.
3. Hacía cuatro años que Juan vivía en Nueva York cuando Enrique decidió mudarse. This is the structure used in Spanish to show how long something had been going on in the past (pluperfect) when something else happened: Juan had been living in New York for four years when Henry decided to move. Looking at this example, in English or Spanish, we can't know how long ago Enrique/Henry decided to move. We only know it that when he did decide to move away, Juan had been living in New York for four years.
Students need to recognize the structures of these three basic sentences, of which there are some permutations -- particularly where questions are concerned. But this is the starting point.
What they all have in common is this: some form of hacer, followed by que + a time period followed by a conjugated verb.
The first sentence has a structure that uses hacer in the present (third-person singular), the time period, then the conjugated verb in the present indicative.
The second sentence, the one that corresponds to the use of "ago" in English, uses hacer in the present as well, and the same structure as the first sentence, but the verb expressing the action is in the preterite.
The third sentence uses hacer in the imperfect, and follows the structure of the other two, but the verb expressing the action is in the imperfect.
Once again, the only way for English-speaking students of Spanish to ever master these is to memorize the three pairs of sentences as models, then be required to recreate parallel sentences in a grammar-translation mode (no, I don't care if anyone thinks of this as outmoded... this is the only way to really grasp this structure intellectually and internalize it).