Why does frío have an accent?
Is it, again, just one of those things? Or is there a reason, because I´ve been taught at school that the reason they have accents is for emphasis on the letter, normally the emphasis should be on the second last vowel. In this case, the i is already the second last vowel and so, why does it need an accent?
Gracias 
10 Answers
normally the emphasis should be on the second last vowel
It would be more accurate to say "normally the emphasis is on the second to last syllable"
When a weak vowel (such as "i") and a strong vowel (such as "o") form a diphthong, the stress (if it's on that syllable) would normally fall on the strong vowel. In "frío" the stress falls on the "I", so one writes the tilde to reflect that fact.
After reading this article, it looks like putting the tilde over the weak vowel breaks the dipthong into two syllables while also putting the word's stress on the letter with the accent. However, putting it over the strong vowel essentially causes the syllable containing the dipthong itself to be stressed (when it normally would not be) while also maintaining the relative stress between the two sounds in the dipthong.
Just a trivial fact. Rather than saying that the accent mark shifts the stress to the weaker vowel in a diphthong from the normal, strong vowel, I have usually heard it expressed as the accent mark prevents a diphthong from being formed.
That being said, if the io formed two different syllables (diphthong prevented) (fri-o) then the accent would be on the I (grave) where the accent mark shows it.
I've never bothered to look up the word, but if the dipthong is formed it would be frio (one syllable) with the I stressed. If the diphthong is prevented from being formed, it would be fri-o (two syllables) with the stress on the I.
Sometime when I'm not so lazy, I'll find the site that breaks words into syllables and see which is true. (don't use our dictionary because it breaks words into phonetics to show how it is pronounced, not into true syllables.)
If anyone knows off the top of their head whether it is frio or fri-o post it. (one or two syllables). The letter I receives the stress (the accent mark) in either situation, either to shift the stress from strong to weak vowel or to prevent the diphthong from forming.
According to this site it is fri-o, so no diphthong was formed or there would only be one syllable. (note-these syllabication sites are notoriously inconsistent).
That's not an accent, that's a goosebump
I think that the real question is...Is there a difference between io and ió.
My understanding so far is that placing the accent over the strong vowel within a dipthong would cause the dipthong itself to be accented within the word when it would not normally be accented. At the same time, the relative accent within the dipthong itself would also be preserved (thus, pronunciation of the dipthong doesn't change between io and ió, only how io is stressed as a dipthong within the word).
Contrast cancion (which is not a word) against canción (which means song). Cancion would be pronounced approximately /CANTS-y?n/ while canción would be pronounced approximately /cants-Y?N/. However, in either case, the io gets pronounced approximately /yo/ because within the dipthong itself there is a relative accent /?-?/ (whether or not the dipthong as a whole receives the accent within the word).
On the other hand, placing the accent over the weak vowel (as is done in frío) in what would otherwise be a dipthong causes the weak vowel to become a strong vowel, thus breaking the dipthong. So far as I can tell, there is no such thing as "shifting the stress within the dipthong." Rather, it seems there are only two choices:
- Causing the dipthong as a whole to receive stress when it is not the next-to-the-last syllable (by putting the tilde over the strong vowel) and
- Breaking the dipthong (by putting the tilde over the weak vowel).
The reason I say this is because a dipthong always has a pattern of {weak vowel / strong vowel} or {strong vowel / weak vowel}. But once a tilde is placed over the weak vowel, the pattern becomes {strong vowel / strong vowel} which cannot produce a dipthong in Spanish (like the ae in maestro, which is not a dipthong, and thus it is pronounced as /m?-?S-tro/).
Or, at least, this is how I understand it currently. And, again, this perception is all based on my reading of this article.
Consider the 3rd pers sing preterit of of "ver ("vio"). One syllable, no tilde, stress on the "o"
I don't follow your point.
In vio a diphthong is formed and the accent is on the strong vowel as the rules say that it should be.
If we wished to shift the accent to the weak vowel, you would need an accent mark (vío) or if we wanted to prevent the diphthong from being formed we would have to write vío. Since the diphthong is formed it is one syllable. Your example substantiates everything that I said, so I don't understand what you are trying to say.
If the accent mark is used to either shift the stress from strong to weak vowel it would still be one syllable (diphthong formed). If the accent mark blocked the formation of the diphthong there would be two syllables. As there is no accent mark, neither case applies. We were discussing what the addition of the accent mark actually does. What does the addition of the accent to the word frio do? Shift stress within a diphthong or prevent a diphthong from existing. To decide which is the case you need to look at how many syllables the word has.
From what I have read concerning diacritical accent marks (those that are only there to distinguish words from each other like el, él, esta, ésta) there is no difference in the way that they are pronounced.
That is my understanding too. There was a time when one wrote "fuí" and "fué" and other words with accent marks that were not really needed for phonetic reasons. However in the late '50s or the '60s the RAE revised their stance on this; restricting their use to making semantic distinctions (preserving, of course, the use for real differences in pronunciation).
Are you saying that the io of frío and the io of vio are pronounced differently?
Of course, the ío and io are pronounced differently. In the first the stress is on the i and in the 2nd the stress is on the o.
But I would be the first to admit that I know absolutely nothing about Spanish pronunciation. I think that the real question is...Is there a difference between io and ió. From what I have read concerning diacritical accent marks (those that are only there to distinguish words from each other like el, él, esta, ésta) there is no difference in the way that they are pronounced. So io and ió are pronounced the same.
Back to our case ío in frío. The question is whether ío and í-o are pronounced the same. (The one syllable word with a diphthong with the weak vowel stressed and the one with two syllables í -o. I Believe they are pronounced differently as there is a hiatus or pause inserted between the two syllables, but a native would have to answer that question.
Originally, I only meant to insert a trivia comment and not hijack the original thread. For further explanation, see the thread posted concerning how to pronounce oír and read dandi's reply concerning breaking the diphthong with the accent mark.
I've never bothered to look up the word, but if the dipthong (sic) is formed it would be frio (one syllable) with the I stressed.
Consider the 3rd pers sing preterit of of "ver ("vio"). One syllable, no tilde, stress on the "o"
en la I lleva acento la palabra frío
