Expert: Erin E. Maio-Harrison, MA,CCC-SLP - 10/14/2005

Question
1. what is the significance of stress or accent?
2. what is the comprehensive definition of stress or accent?

Answer
Hello Alyssa-
What an odd question...sounds like homework to me.  Linguistics Homework.  Or a bet.  Well, I will do my best.

I think we should define the terms before we start discussing their significance.

My Google search for definition resulted in the following:  
"accent: In linguistics, stress is the emphasis given to some syllables (often no more than one in each word, but in many languages, long words have a secondary stress a few syllables away from the primary stress, as in the words cóunterfòil or còunterintélligence)."
en.wikipedia.org/wiki/Stress_accent

"stress: the relative prominence of a syllable or musical note (especially with regard to stress or pitch); "he put the stress on the wrong syllable"
wordnet.princeton.edu/perl/webwn

I am guessing that you meant "accent" as it relates to "stress" and not in terms of a regional accent.   And I assume that by "stress" you meant it in terms of syllables and not words.  If you want something more comprehensive, any dictionary (web or otherwise)will list at least several paragraphs of definitions for each word.

And don't forget tone!  In English it can be used to signal a question, sarcasm, regional dialect. It's the musical element of language.  In Mandarin tone is phonemic. My girlfriend was learning it for her wedding and said there were several different ways to say the word "ma", all with different tones, all with different meanings, and the incorrect pronunciation would result in a really inappropriate word to say in front of the in-laws.

As far as significance, in English accent and stress are not phonemic at the syllable level, meaning that if you stress the wrong syllabe it doesn't change the meaning. (there might be a few exceptions) It sounds really odd and makes people wonder where you are from or what's wrong with you but they understand the words.  I seem to remember in high school French that incorrect use of the accent grave changes the word, so that is phonemic.  Now stressing individual words does change meaning in a subtle way, for example the sentence "I walk home."
"I" walk home.
I "WALK" home.
I walk "HOME".

This is often an area of great difficulty for foreign speakers of English.  Even when they get the sounds right, the proper stress often euludes them, and they still sound "accented".  Listen to an exaggeraged accent on TV (done for comedy) and you will hear not only sound errors but stress errors.  Thinking of a French accent and the word "Happy".  You might hear the actor say, "Ah-PEE", dropping the /h/, changing the stress to the second syllable.

Hope that answers your question(s).  Good luck on that assignment or winning the argument-

Erin E. Harrison, MA,CCC-SLP
Speech/Language Pathologist