Past perfect or preterite?

Hola Peter -

For me, the best indicator that we need to use the "Pretérito Perfecto" - is that there needs to be some sort of link to the present situation. In the example you give, it very much depends on the context. As an exercise in using the "Pretérito Perfecto", you can assume that in this case there is currently some type of 'follow-up' or consequence relating to the demonstration.

There is in fact a pretty good correlation between the use of the "have ..." construction in English and the "Pretérito Perfecto" in Spanish; i.e., if "have [seen] ..." sounds better in English, then translate it as "he [visto] ..."

I did, however, come across an interesting exception:

Immediately after a really spectacular lightning-flash in the sky - in English, people would often say: "[Holy Moly] - did you see that lightning display?" [rather than "Have you seen ...?"], whereas in Spanish you would often hear "[Madre mía], ¿has visto ese relámpago?

The use of 'hoy' or 'este año' etc. is sometimes cited as a guide that the "Pretérito Perfecto" is recommended, but my Grammar book says that there is flexibility about that [varying with different regions in Spain and Latin America] - e.g. "This morning I went to the dentist" could be translated as "Esta mañana fui al dentista" if [by the evening, say] you regard it as something finished  (and best forgotten !)

Hola Peter,

Yes the event has finished, but the Pretérito Perfecto is principally used for time frames which are "current," such as today, this morning, this week, this month, this year. The key word here is "this." As this is a lesson about the Pretérito Perfecto, it is implied that the event happened at one of these periods; so for example "Paco saw the demonstration [this morning]." Very often they do not translate the verb hacer (has seen), but use the past tense translation (saw). The teachers will always give a hint in the quiz if there is any doubt about what time frame they are referring to.

In English we use have + the participle far more often than in Spanish, where these definitions are quite specific and fixed. In English "I saw the headline in the newspaper" strongly implies a current period as does "I have seen the headline ...." whereas the latter is probably more correct. We bend the rules far more often I think.

For the record the Pretérito Perfecto is also used for life events such as "I have been to Cordoba and visited the Mezquita / I have had my tonsils removed" In this usage there is a lot of correlation with English. Invariably they translate the "have" in this context.

Saludos.

John