The sounds are best characterized by what causes them. A poof is generally the sound that, say, a cupcake produces when hit against a wall, whereas the thud is more likely to be caused by a muffin-like projectile.

If you threw a cupcake against the wall, you would hear something of a "poof!" If you threw a muffin, you would hear a "thud!" Mohoahaha! Great explanation, Bratannia.

Is there a difference between a cupcake and a muffin?

From GuruNet: Please adv. If it is your desire or pleasure; if you please. Used in polite requests: Please stand back. Pay attention, please. Yes. Used in polite affirmative replies to offers: May I help you? Please.

Yes, in formal contexts. But in everyday spoken language, you can use "there's," even before a noun in the plural.

find and find to be can both be used.

What does the expression "no windows" mean? Can't find it in my dictionary. ...Never mind...

Why is "The car is washed" incorrect? Is "The car is always washed on Wednesdays" incorrect too?

Fast is an adverb as well as an adjective, isn't it?

The reason why there are so many forms is that 'be' has somehow avoided to be affected by certain changes that has occurred to English grammar over the centuries. If you look at Old English, you will find that all verbs were inflected according to