The Spanish language uses emphasis (or stressed vowels) and accent marks.
Stress is applies to a vowel in a specific syllable of a Spanish word.
The accent marks for specific Spanish vowels (acute accents) are used for written words that do not follow the rules for applying stress to Spanish words.
(Note: The use of the word “accent” does not refer to pronouncing Spanish as if it were an English word; i.e., “speaking with an accent.”)
Applying stress correctly to Spanish words means that the Spanish that you pronounce will be understood by native speakers.
The first thing to remember is that only vowels receive stress in Spanish words.
The second thing to remember is that just about every Spanish word has a syllable with a stressed vowel. These stressed vowels can be “marked” or “unmarked.” One syllable words can contain a stressed vowel.
Spanish words must receive the stress when pronounced, even if the vowel that must be stressed is not marked with an accent when the word is spelled.
Written Spanish also uses accents marks to differentiate words that are spelled the same and sound the same (homonyms) but have different meanings. For example:
que and qué
Si and sí
te and té
An obvious conclusion: Reading Spanish words with English rules for applying stress is incorrect. Reading Spanish using English rules for placing a stress on a vowel sounds terrible to a native Spanish speaker.
Language learners often overlook practice for using stress in Spanish because language learners focus upon pronouncing the Spanish words correctly. But, producing the sounds of the letters is not quite enough.
Stress must be added for the correct vowels before students master Spanish pronunciation.
Fortunately, learning the rules for using stress in Spanish is much easier than learning the sounds used in Spanish pronunciation. There are only a few rules, and the rules are consistent.
Unfortunately, accent marks must be entered for every word that applies a stress for a vowel, when that stress that does not follow the basic rules for accent use. And, the only way that you can know which words must receive a written accent is by memorizing those words.
Another “Gotcha”: You must use “Alternate Character Codes” to type the accents on Spanish words if you are using an English keyboard. (Another slide in this presentation describes how to do this.)
And, unless you are immersed and working in a Spanish-speaking country, don’t even consider switching between an English and a Spanish keyboard. The number of &Alternate Character Codes" that you have to learn is small, and the &dissonance" you face when learning two keyboard layouts is troublesome. (This would be like driving one car with the accelerator peddle on the right and driving another car with the brake peddle on the right. Disaster!)
Vowel Stress Practice Advice: Practice stressing vowels in isolation (by reading word lists) to get the rhythm and feel for using vowel stresses correctly. Practice vowel stresses by speaking Spanish sight words, Spanish words that are used with high frequency, and words used in basic conversation.
Become confident in using Spanish vowel stresses.
Then tune your ability to stress the vowels of Spanish words during normal conversation by listening for the stresses that native speakers use. The accurate use of accents will contribute to your language fluency, and decrease your "foreign" (English) accent.