the vowel symbol

Question

hola! can someone help me what is the use of this ( ' ) symbol in writing a vowel letters'

Answer 1

http://www.spanishdict.com/reference/grammar/accents

Above is a link to the Spanish rules for pronouncing a word. Included are rules for where to put the stress in saying the word. When the word calls for placing the stress somewhere other than where the rules suggest you use the accent mark to show that location. Where the stress is placed is very inportant as it may actually change the meaning of the word. Example:
ÿsta=this one (pronoun)
Está=to be (he/she/it/you as subject) (verb)
Esta=this (adjective)

como=I eat (verb), as, like (preposition)
cómo=how

¿Por qué....?
¿Cómo...?
¿Cúal...? Spanish sometimes used the accent not to change the stress, but the part of speech. que is usually used as a relaive pronoun to introduce a clause. In ¿Por qué? the accent does not change, but the meaning does and it changes the part of speech to that of an interrogative pronoun.

Answer 2

HI sharnie, at last..this is an adequate title, thanks.

The ' on the vowels indicates the fonetic stress. So, the stress falls onto the stressed vowel.