I wouldn't use any words.

I don't know if it sounds "smart", but I always admire someone who is able to incorporate the word "melifluous" into a sentence without sounding pretentious.

Big ones, maybe, if I knew them and knew what they mean. Maybe things like amorophous, osmosis, vague, elaborate. . .

You should worry more about being smart then sounding smart. Trust me I was a moron when I was in middle school because I used big words cause I wanted everyone to think that I was smarter then I was. Its just not worth it. Personally I'm a fan of Apocalyptic ramifications of epic proportions.

I would express myself in a clear and simple way so that I could communicate my message most effectively.

Words spoken from the heart with presence.

The right ones.

It depends on what you're talking about, and how much you know about it. There are a lot more pitfalls to sounding smart then there are words that could do it. It is always better to use small words and make a clear point, than to use large words that could end up obscuring it. NEVER try to use industry jargon of you are unfamiliar with it. I have heard this done with disastrous, and hilarious, results. You don't want to end up as the butt of a joke. If you are writing, it is quite acceptable to use the thesaurus for alternate words. You must be familiar with the replacement word you select, however, because even a word with the same meaning as another may not fit well in the same place. Never assume the person you are talking to doesn’t know what you’re talking about and try to bluff your way through a subject. It will inevitably turn out that they are an expert in that area. I have always found that when I don't know much about a subject, I sound smarter (or at least people later tell me that was their impression) when I ASK questions instead of trying to act like I know all about the subject. This works especially well if you know quite a bit about something you can relate to the subject at hand. i.e. If you know nothing about taxis, but have a knowledge of trucking you could say something like "I don't know much about taxi driving. Are there vehicle inspection requirements similar to those in the trucking industry?" Later, you could ask another question relating to how break-even is figured in comparison to your knowledge of the methods used in trucking. Even when you have some knowledge of the subject at hand, a few well placed questions can impart an impression of intelligence. (WOW, alliteration! That is a fine example of what not to do, so I’m leaving it here.) That said, and since I seem to be on an “I” kick. My current favorite “smart” word is impetus.

id use the word prefer rather then saying want

i'm not saying you are, but if you aren't smart, whats the use of sounding smart? one of my favorite ever quotes says: "Better to stay silent and be thought a fool, then to speak up and remove all doubt."

I would stay silent. You can't be called a fool if you don't act like one.

I'm already too smart for my own good. :-)

Arrogate, obfuscate, phantasmagoria, stipple, hirsute, quell, craven, natter, and atrophy are a few for sounding smart. Knowing their meaning and using them correctly is imperative however.

To be obtuse in the face of reciprocity is nothing short of superfluous.

I find that the word "fabricate" works well in place of "make." But I can argue that it's not so much what words you use or the size of the words, but rather the way that you use them.

like intellegence or maybee intellegent instead of smart!

I'd rather be smart than sound smart. A smart person is someone who can explain complicated ideas using simple language.

I'd listen first. Then I'd say little.

Words that I can spell correctly. :)

English has a Germanic (Saxon) influence and (since 1066) a Latin influence. The smart-sounding words are the Latin ones. To this day, many people get hostile at you if you use Latin words -- they call you a poindexter, etc. I think this is left-over resentment against the Norman conquerors.

I hate when people 'try 'to sound smart. It makes them look stupid to me

using certain words is not what will make you sound or appear smart. being able to use the words you know to express your ideas, thoughts, opinions, suggestions, and comments it what will make you seem intellectually intelligent. if you know what you're saying, and can clearly communicate it, you will put on the facade of "smart". but on the other hand, the idea of being "smart" is not limited to the words that come out of your mouth. "smart" also very much includes the decisions you make and your ability to act with grace under pressure. it also includes the mistakes you make, and how you learn and grow from those mistakes. "smart" is not achieved by simply spewing large or complicated sounding words out of your mouth. 98% of communication is non-verbal. keep that in mind. what really makes you smart?

Just use words that you know...Don't try to impress people with vocabulary...It will backfire on you.