1. ¡Los acentos!

2. There are two basic rules in Spanish that tell us where to put the stress of a word. Stress is important, as it can sometimes be the only way to distinguish two words. It’s the difference between “insult” (IN-sult), as in “I couldn’t think of a good insult,” and “insult” (in-SULT), as in “She’s going to insult me now, I just know it.”

3. Intentalo…
Intelligent
Responsible
Punctual
Generous
Respectful

4. 1. Words ending in a vowel, n, or s.
For words that end in a vowel, the letter “n,” or the letter “s,” the stress is on the next to last syllable.
Examples:
   todo (to-do) all/every   inteligente (in-te-li-gen-te) smart
   el examen (e-xa-men) exam   joven (jo-ven) young
   lunes (lu-nes) Monday los calcetines (cal-ce-ti-nes) socks

5. 2. Words ending in a consonant (not n, s)
For words that end in all other consonants (not “n” or “s”), the stress falls on the last syllable.
Examples:
     comer (co-mer)to eat  la ciudad (ciu-dad)  the city
    el animal (a-ni-mal)the animal   Madrid (Ma-drid)  Madrid
el profesor (pro-fe-sor)  the professor/teacher
   

6. When to add Spanish accent marks
We add accent marks to Spanish words when the stress breaks either of those two rules.
Example:
exámenes (e-xa-men-es)
The word ends in an “s”, so according to the first rule, the stress should fall on the next to last syllable: ex-am-en-es. But it doesn’t.
Rather, the word keeps the same stress as its singular form, on what is now the third to last syllable, so we add an accent mark.

7. Más ejemplos (rule 1) la canción (can-cion) song
   también (tam-bien) also
   los crímenes (cri-me-nes) crimes
   jamás (ja-mas) never
   inglés (in-gles) English
  rápido (ra-pi-do) fast
   está (es-ta) is, third person singular of the verb estar – to be

8. Más ejemplos (rule 2) el árbol (ar-bol) tree
     la cárcel (car-cel)  jail/prison
     el césped (ces-ped)  grass
     débil (de-bil)  weak

9. Spanish homonyms: Same pronunciation, different meaning
 el (masculine article: the)      él (he)
     mas (but)      más (more)
     se (reflexive and indirect object pronoun)      sé (I know)
     si (if)      sí (yes)
     te (object: you)      té: (tea)
     tu (your)      tú (subject: you)

10. Accents on Spanish question words
 Who? ¿ ?  What?   ¿ ?
When? ¿ ?  Where? ¿ ?
 Why? ¿ ? How? ¿ ?
  Which?   ¿ ? How much/
How many? ¿ ?
     

11. Indirect embeded questions.
Whenever the word “cuánto” means “how much/many,” it carries an accent:
Ej.  No sé cuántos hay. (I don’t know how many there are.)
When the word “cómo” translates to “how,” it carries an accent – no matter where it falls in the sentence. (Without the accent, “como” means “like” or “as”.)
Ej. No entiendo cómo lo hace. (I don’t understand how he does it.)
Likewise, when “qué” means an interrogative “what,” it must carry an accent.
Ej.  No sé qué hacer. (I don’t know what to do.)

12. As pronouns; no accent mark!
When these words are not used in a question or indirect question, but rather as a pronoun, there is no accent mark. Here are three example sentences of this situation:
Ej.   El chico que dijo eso es mentiroso. (The boy who said that is a liar.)
Ej.  Es el parque donde conocí a tu madre. (It’s the park where I met your mother.)
Ej.  No trabajo cuando estoy enferma. (I don’t work when I’m sick.)

13. Finally… Demostrative pronouns
Spanish accents are used in feminine and masculine demonstrative pronouns (this one, that one) to differentiate them from the demonstrative adjectives (this –, that –), which are identical except that they don’t carry an accent mark. Pronouns: replace nouns. Adjectives: describe nouns.
Ej. Masculine éste (this) éstos (these) ése (that) ésos (those) aquél (that over there) aquéllos (those over there) Feminine ésta (this) éstas (these) ésa (that) ésas (those) aquélla (that over there) aquéllas (those over there)
Neutral
 esto  (this)  eso (that) aquello(that over there)