This is pretty nice for a rough draft, but I have a lot more information on all of these languages and dialects, including lots of links. But this should do for now.
Spanish or Castillian hit the other languages hard, but after the dictatorship things got a lot better.
Catalan is the official language of the region. Catalan is not part of Macro-Spanish. Instead it is part of a larger family called Catalan-Occitan. I recently met several mostly-Castillian speakers from Catalonia and they told me that they all understood Catalan. Whether they spoke it or not was another matter. A young man there was a native speaker. Native Catalan speakers might be ~35% of the population, and many children are still being brought up in Catalan.
There are Catalan schools, Catalan media, Catalan as an official language in the government, etc. There is a huge pool of Catalan second-language speakers. There are probably not any Catalan monolinguals left, but if there are, it is some old lady in a tiny village in the mountains.
Island Catalan is a form of Catalan that is spoken on the Mallorca Islands in three different dialects. Some have difficult intelligibility with Catalan, and they are probably closer to Valencian. Whether these qualify as separate languages is not known. Mallorcan is one of these dialects of Catalan.
Valencian is spoken in Valencia and the Valencian speakers insist that they speak a different language from Catalan, although there is 94% intelligibility between the two. Catalan speakers do not want to break up the language. There is an Institute of the Valencian Language, an official orthography, etc. In particular, Valencians reject the Catalan orthography, as they say it does not suit the language that the speak. ~20% of Valencians speak Valencian. It is in much worse shape than Catalan. The Catalan authorities refuse to recognize Valencian as it is just a Catalan dialect, first, and second because they see Catalan as endangered and they do not wish to split it up.
Chapurillo is a form of Catalan spoken in La Franga and the Strip in Aragon that speakers say is a separate language. There are regular calls to have it recognized. However, Catalan speakers say that they understand this variety perfectly. Nevertheless, an attempt to call this dialect Catalan and have it translated into English resulted in a big mess. Its name is a variation on the term churro, etc. which means more or less broken Spanish or bad Spanish.
Many of the languages above are called churros or chapurros, and many Spaniards think they are just forms of broken Spanish spoken by poorly educated people. Even speakers of the languages often think that they simply speak broken Spanish or bad Spanish and are often ashamed of their speech and refuse to speak it. Speaking churro also implies ignorance, rural residence, poverty, lack of intelligence, etc. Any effort to get this lect recognized would run into a lot of opposition from the Catalan government, which would say is is just a form of Catalan, which in fact it is.
Aragonese is still spoken in Aragon. It is not fully intelligible with Castillian, and it is a separate language. This region was under the crown of Aragon, hence a different speech evolved here. It sounds a lot like Spanish. There are 30,000 Aragonese speakers. It is an official language in the state of Aragon, but Spain refuses to recognize it as it is seen as Macro-Spanish, which it is. It was formerly spoken in three forms like Extremaduran, and like that language, only the remote northern form survives.
Otherwise Southern Aragonese and Central Aragonese turned into dialects of Spanish called Aragonese Spanish. Aragonese is spoken in the very high mountains of the Pyrenees in villages that are often almost totally depopulated. There are still children being brought up in Aragonese though, especially around the Benasquesque-speaking region. The children show up at school as Aragonese monolinguals.
Churro is a Spanish dialect called spoken around La Franja on the border of Aragon and Catalonia. It is probably the most diverse dialect in Spain. It seems to be a form of Aragonese Spanish with a lot of Catalan or Valencian mixed in. It is not known how widely spoken this dialect is anymore. It’s apparently intelligible with Spanish, but an attempt to call a Churro text Spanish and translate it into English resulted in a complete mess.
Basque is actually doing quite well. ~20% of the population are native speakers, and there are quite a few second language speakers. There are Basque schools, Basque media, Basque signage, on and on. I recently met a young college-aged man who was a Basque native speaker. Quite a few children are still being brought up in Basque. I am not sure if there are any Basque monolinguals left. Basque is not related to any of the languages spoken in Spain. It is the remains of the original language of the area before it was conquered by the Romans. Basque is recognized as by the Spanish government.
Souletin is absolutely a separate language from Basque Proper or Official Basque. There are other dialects including Guipuzcaon and a few others which may also be separate languages, but that is much less clear. Souletin is spoken in France, where Basque is spoken by only 10% of the population.
Asturian-Leonese is a major language spoken in northern to northwestern Spain between Basque and Extremaduran and Galician. To the south, it extends to the Portuguese border. It consists of two major dialects, Asturian and Leonese and countless dialects therein. However, comprehension appears good between all of the Asturian and Leonese dialects, except that part of Eastern Asturian in the north and Eastern Leonese in far south have turned into a separate language called Extremaduan-Cantabrian.
Asturian one part of the Asturian-Leonese language. It is still very much alive, although it is not an official language of Spain. It is an official language of the state of Asturias. ~20% of Asturians speak Asturian and I believe there are children still being brought up in Asturian.
Leonese is the same language as Asturian spoken to the south and is in much worse shape. It is also not an official language of Spain, but it is an official language of Castille and Leon where it is spoken. Amazingly, there are still Leonese monolinguals in the high mountains in Northwestern Castille and Leon. Leonese was their first language and they learned Spanish in school but subsequently forgot Spanish and now speak only Leonese.
There are still children being brought up in Leonese in the tiny depopulated villages in the mountains of Southeastern Castille and Leon near the Portuguese border. This form of Leonese is often called Porteno, and it is quite close to the Mirandese language spoken in Portugal. Asturian-Leonese is seen as part of the general Castillian language family, but this is not really true.
Mirandese is spoken in a small part of northwestern Portugal by 15,000 people. It is a form of Asturian-Leonese that came under heavy Portuguese influence and became a separate language. It is similar to the Porteno form of Central Leonese spoken near the Portuguese and Galician borders of Castille and Leon. Mirandese proper is spoken in Portugal, but other dialects of it are spoken in a few small villages on the Spanish-Portuguese borders. Most of these are considered to be extinct, but recent field trips found that they are still spoken in a few of these places.
Rio de Onorese is a tiny lect spoken in Rio de Onoro, a village on the Portuguese border. Half of the village is in Spain, half of the village is in Portugal and all residents are fluent in both languages. Everyone thinks this language is extinct, but if you go to the village, you will see it is still spoken there. It is a form of Mirandese spoken in Spain and should be recognized. It is a form of Asturian-Leonese as Mirandese is part of that language family. As a form of Asturian-Leonese, this is not recognized by the Spanish government. However, Mirandese is recognized by the Portuguese government.
Eonavian-Ibino is a separate language spoken between Asturian/Leonese and Galician. Locally it is referred to as fabla. It is a completely separate language but no one will recognize it as such. It even has an organization for the standardization of the language. The name Eonavian is a reference to the Eo and Nava rivers in the area where it is spoken. Ibino is this same language spoken in the southern part of the Eonavian area and it borders Leonese instead of Asturian.
Galician speakers cannot fully understand Ibino. It is closer to Galician but it is not Galician. At one time, maybe 75-100 years ago, this was a Galician dialect, and the older generation still understands Galician completely. The younger generation does not understand Galician so well, as they have not been exposed to it as much. So in a sense this is a new language or an emergent language. There are still many native speakers of Ibino and Eonavian.
As is usual in such cases (see Benasquesque below) the language institutes of both the Asturian/Leonese language and the Galician language have claimed this language. It’s certainly not Asturian/Leonese. A much better case can be made that it is Galician, and it was a Galician dialect until quite recently. However, Eonavian informants state that when they go to Galicia, they speak Castillian to Galician speakers results in too many misunderstandings. Since both Asturian/Leonese and Galician claim this lect a dialect of their languages, Spain does not recognize it.
Galician is is a separate language spoken in Galicia that is close to Portuguese. It is still doing quite well. ~35% of the population of Galicia speak Galician. Almost all also speak Castillian. It is an official language of Galicia and Spain. There are Galician schools. There is some Galician media but not nearly enough. You hear Galician a lot more in the rural areas than in the big cities.
A very Castillianized Official Galician is used in the media, and it has high intelligibility with Spanish of 78%. A much harder Galician is spoken in the villages in the mountains where intelligibility with Spanish is as low as 40%. The form of Galician spoken in the far south on the border with Portugal is not intelligible with Portuguese or the rest of Galician and is not understood outside the region. It is actually a separate language, though no one will recognize it.
Minhoto is a form of Galician that is spoken in and around the Minho region of Portugal and the part of Galicia neighboring it to the north. It is generally not understood outside the region. It appears to be an aberrant form of Galician that perhaps came under heavy Portuguese influence.
Fala is a language spoken in the far northwest of Extremadura near the Portuguese border. It is spoken in four different dialects in as many towns. It is still very widely spoken as a native language in all of these towns. This is Old Galician from the 1200’s that got isolated from the rest of the language and underwent heavy influence from Leonese, especially the Asturian-Leonese language spoken in Portugal called Mirandese.
Technically this is not a separate language as Galician speakers understand it perfectly, but it is nevertheless recognized as a language by SIL. Fala speakers reject the Galician orthography as far from what they speak, adding ammunition to the notion that this is a separate language. Spain does not recognize this language for whatever reason, but if it is a part of Galician, it should at least be recognized as that.
Portuguese is spoken in a few places in Spain on the border of Portugal, mostly in the South around Extremadura and Bajadoz. These are forms of Old Portuguese dating from the 13th to the 16th Centuries. However, they all seem to be fully intelligible with Portuguese. They are mostly spoken by the elderly now.
Oliveno is a form of Portuguese heavily mixed with Spanish that is spoken on the border of Portugal. It’s not Portuguese; it is actually a separate language. It still has ~3,000 speakers. It is spoken in a single village. Officials refuse to recognize this language, and Portugal says it is just Portuguese, but Portuguese speakers can’t understand it at all. Spain refuses to recognize it for whatever reason, but if the argument is that it is just a form of Portuguese, then it should be recognized.
Extremaduan-Cantabrian is a language spoken to the east of Asturian in the north and to the south of Leonese in the south. These are parts of Eastern Asturian-Leonese that got isolated in the mountains of Cantabria and Extremadura and split off from the rest 500 years ago. In the north, it went into Cantabrian and in the south, it turned into Extremaduran.
Extremaduran is still spoken in Extremadura by 100,000 speakers. It is a highly Castillianized form of Eastern Leonese that got cut off from the rest of Leonese 400-500 years ago. Otherwise Eastern Leonese is nearly extinct. However, it is not intelligible with Asturian-Leonese. Extremaduran speakers say that if they go to Oveido in Central Asturias, they will not be understood. Nevertheless, this is part of the same language as Cantabrian, and these same speakers say that if they go to Cantabria, their Extremaduran will be understood. It is spoken in the mountains in tiny depopulating villages, which is where it originated.
One of my Castillian-speaking informants actually grew up in the region and has been hearing Extremaduran all his life, and he can only understand 17% of it. The accent is wild. There is much confusion, as Extremaduran is also called Castuo. Extremaduran is the northern form of Castuo from the mountains that survived, while Southern Castuo and Central Castuo turned into dialects of Spanish.
However there may be some “Extremaduran” spoken in the south too, as an informant has a word list from a tiny village in Bajadoz, and he said he could only understand 50% of the lexicon. This may be some far southern form of Extremaduran. Southern and Central Castuo are just Spanish dialects, albeit odd ones, but they are heavily spoken and often confused with Extremaduran because people refer to both by the same term. Extremaduran is an official language in Extremadura, but Spain refuses to recognize it because it is seen as part of the larger macro-Spanish although it is actually Asturian-Leonese.
Cantabrian is part of the same language as Extremaduran. This is the Asturian form of Asturian-Leonese that got cut off from the rest of Asturian 400-500 years ago and became very Castillianized. Cantabrian is not fully intelligible to Spanish speakers. It is still alive in the mountains where the children come to school as Cantabrian monolinguals, and the teachers from outside the region say that they can’t understand these children.
Mantegno is spoken in La Mancha and is part of a “Southern Castillian” that ranges to Andalucian and probably also includes Murcian. When Mantegno speakers go to Madrid, they say they are not understood. This is probably also a separate language. When spoken in rapid speech, intelligibility even with Castuo is 50%. Of course it is not recognized by the state as even native speakers hardly realize that it is a separate language.
Andalucian is mostly a Spanish dialect called Andalucian Spanish, albeit an extremely divergent one. However, there are a few villages in the mountains in the south where a hard Andalucian is spoken that is not intelligible even to other Andalucians. It would be valid to regard this form of Andalucian as a separate language, but no one is going to split it off.
There is also a hard Andalucian of the street associated with criminals and other street types. People from Northern Spain say they can’t understand it at all. There have been efforts to get Andalucian recognized by the state, but they always fail because all that remains is a Spanish dialect, and even if it were a separate language, Spain would argue that it is part of Macro-Spanish, which it is.
Murcian, spoken in Murcia, is mostly a Spanish dialect called Murcian Spanish, albeit quite a strange one. There are regular calls to have it recognized as an official language, but they go nowhere because it’s not really a separate language.
However, there is a hard form of it called Panocho spoken in the remote mountains in Eastern Murcia that cannot be understood outside the region. Andalucians cannot understand it either. It is probably a separate language. It has 6,000 speakers. There are efforts to get this recognized by the Spanish state, but they never go anywhere as what they try to legalize is simply a Spanish dialect called Murcian Spanish. The harder Panocho form would also not be recognized by Spain as they would see it as part of Macro-Spanish, which it is.
Aranese is a form of Occitan spoken in the tiny state of Andorra. It is still spoken by people of all ages, and children show up at school speaking Aranese. Although it is intelligible with the Occitan spoken directly across the border in the French Pyreneees, it is not fully intelligible with the rest of Occitan. It is not well understood by speakers of any of the surrounding speech forms. Aranese is actually recognized as a separate language by Spain.
Benasquesque is a form of speech spoken on the border of Catalonia and Aragon in the very high mountains that cannot be definitely shown to be either Catalan or Aragonese. It is certainly not Aragonese. It could be Catalan, but a Catalan informant told me that this lect is absolutely not Catalan. However, the official language institutes of Catalan and Aragon both claim these speech forms.
But as is usual in these cases, they are both wrong and it is a separate language altogether. This is a very remote mountain region. This is a sort of microlanguage transitional between Aragonese and Catalan. Since both Aragonese and Catalan language institutes claim this language, it is not recognized by Spain and there are no attempts to get it recognized.