Hello prospective respondents. We may have many Spanish citizens here, so just a reminder of which sub we're in: it's /r/AskHistorians so no personal anecdotes, urban myths or conjecture. Respondents here are expected to have expertise in the subject, offer in-depth information and cite reputable sources. Thanks!

OP: if you want less formal (or even more specialized) responses, you might try x-posting to a regional sub like /r/spain (English) or /r/es (Spanish)

TLDR: 1975, Franco died, bad stuff happened during the dictatorship, "pact of silence", and it still remains very taboo

So, civil war in Spain. It was a very complex, multi-layered conflict. for example the Barcelona may days (may 1937, when the Spanish left fought each other over the telephone exchange and other symbols of power), as described in an article by Helen Graham was not only about differing views on what cause the left were fighting for, but had deep roots in the cultural history of Barcelona, that went back decades. It was about how the left should fight the war (the issue of unified command amongst the 10 or so different left wing factions), the poor against the state, and the centre against the periphery. The point i am trying to illustrate here is that most things to do with the Spanish civil war have different layers to them, and can be seen in different lights. the left were not necessarily the "good guys" and the right were not necessarily the "bad guys" as is often displayed in popular fiction. Whilst the left were fighting for very basic rights and modern values, they killed clergy brutally during the opening days of the war (priests crucified, penises cut off and stuck in mouth, you get the idea). Meanwhile the right believed they were fighting against communism, protecting the old order of stability (in the north at least) and acting with the Pope's blessing. However, they also committed atrocities, which continued long after the conflict. So following the war, Franco installed a harsh dictatorship targeted againdt the "other" in society, the enemy within; in essence, the war continued in a sense. Neighbours denounce each other to the falangists as lefties, pupils denounced teachers etc. essentially, those who were not in prison camps following 1939, were made to feel complicit in upholding the regime, either by directly accusing someone they knew, or by complete passivity (although being passive was dangerous at this time). Those in prison camps were often used as slave labour, google the "valley of the fallen", it was built war political prisoners as a monument for those who fought for Franco during the war and "fell for God and Spain". The slave labour included left wing PoWs from the war, as well as those denounced as left wing after the end of the conflict and pretty much anyone "other"; homosexuals, 'new women' (think the most basic feminist, dressing, doing and thinking what they want. trying to hold certain jobs. one lady i remember from my studies was detained for "having thoughts"). Those in the camps suffered tremendously, as did their families who were destined for systematic destitution. if you would like i could confirm but off the top of my head it was about 100 000 who perished in these camps, and roughly 350-400 000 detained overall. although it is hard to say to sure. extra judicial killing was rife.

IMPORTANT PART: Franco died in 1975, and the government began a transition from a rigidly enforced dictatorship to a modern democracy. However, the population had blood on their hands, neighbours and communities had invented charges against individuals so as to avoid suspicion themselves. As such, there was a decision by the politicians to enact a "pact of silence"; that is, the systematic refusal to deal with the legacy of Francoism and fascism in Spain. This meant that there was no 'peace and reconciliation' as in South Africa, or trials for war crimes as in Germany and Japan. officially, people are not allowed to really publicly condemn/condone either side of the war, lay blame etc. Spanish school children are taught history up until the early 20th century, they are not taught the civil war, as it remains a contentious and taboo subject. However, generally the tide is turning, since the turn of the 21st century, people have started addressing the past; archeological digs have been uncovering the remains of those killed without trial, local and amateur historians have started going through recently available archives, and a narrative other than the official one 1939-1975 is beginning to emerge. How people feel about it is difficult to say, as it does remain so taboo, i would guess it is a north/south divide, as the two parts of the country have different histories regarding the civil war. hope this helps, sorry its so long.