A verbal thought (Literally)

Wrote this in my company blog today and since this space keeps languishing every once in a while, I thought I'll update it here

How does the human brain process speech? How does it understand the semantics of language? If there are ambiguities, what mechanisms does it use to resolve? For example lets have a look at these sentences, He is a man of simple wants and He wants money.

Admitted this might be more for people who are interested in Artificial Intelligence or probably wonder how to build systems that understand text. In one of the scenarios that I was working, I came across something fascinating. The words need and want are very interesting. As a noun they really don't require an object action to finish the sentence. They themselves become synonyms. For example look at the sentence He is a man of simple needs. Assuming a machine can process that needs is almost a noun here and can identify the underlying meaning behind needs, you have an absolutely great semantic engine.(I'd use the word semantic as it makes more sense :-) ).

Now here are two interesting sentences :

I need a camera.
I want a car.

In both the cases the verb is a simple verb and requires an object i.e camera or car to complete the sentence. Processing them is a breeze for some of the systems today. Heck! even a rudimentary system developed by us can process these kinds of sentences.

Lets get into a more specific scenario. Now the goal is to understand how verbs like need and want behave. Lets introduce a bit of anarchy (literally) and see if these words behave just the same?.

I need to purchase a car
I want to buy a house in Chennai.

Notice anything different? At first glance you see that there are two new verbs introduced purhcase and buy. Well both of them essentially means the same. You could also add construct to the second sentence. Now you have two verbs in the same sentence. How does your brain resolve? Do these steps happen?

1) Decide that need takes in an object to complete it's meaning.
2) Looking for an object action, come to purchase a car, buy a house.
3) Realize that purchase and buy are two verbs which in turn require an object action to complete their sentence. One cannot literally say I want to buy. There is always the question of What action that follows the verb.
4) Then decide that want to purchase actually points to a desire to verb. i.e desire to purchase.

Essentially when faced with words like want, need, a system cannot just process them alone. It has to look for the other verbs in the sentence which aid in their meaning. So the secondary verb is of more importance or is the deciding factor in the sentence. If any of you can help me figuring out much complex situations, you are welcome. I just am pouring out my thoughts here.

One should marvel at the wonders of the human brain. All of us could handle these sentences even in our first standard. In trying to mimic the brain, I just am stumped at how the brain handles complex things in such simpler steps. As for me, I think finishing the Wren and Martin book again, with a deeper understanding of each of the parts of speech is something that cannot be put down for ever :-).

Correction:I had written this in my company internal blog and Rb corrected me at the parts where I have crossed the text. This is his comment :

In my view it is "I need to act" and that action could be "run" or "purchase a house". The What is not mandatory. The "house" to me belongs to the action of "purchase" and not of "need".

Though "I want to purchase a house" is semantically similar to "I want a house"; they cannot be treated the same. Examples of the form "I went to purchase a house" or "I want to sell my house" show the tie-in of the "house" to the "action" and away from the "want".