First of all, what do you mean dumb spells? If your referring to his constant use of nonlethal spells like expeliarmus, that's because Harry's style is to nonviolently disarm his opponent. Hope i answered your question.
They use special effects to create the awesome spells on Harry Potter.
Lots of spells.
you can use them at the ministry of magic in london. Not really , harry potter is a fantasy story
Because they are witches and wizards.
click on the wand and look to your left and use mouse to navigate through spells
In the books of Harry Potter there is an incredible sorcerer in the stories who can do spells that are very magical.
You can use protego, depulso and stupefy.
Avifors - Turns small objects into birds. Engorgio - Enlarges and item Reducio - Returns items to original size. Counters Engorgio Riddikulus - Use this spell and laugh to defeat a boggart
Harry used one of the spells in the book on Draco Malfoy and almost killed him. He no longer wanted to use the book and so hid it.
Neither Cedric or Harry kill the skrewts, they just use the "stupify" and "impendmenta" spells against them to get away.
yes
Wikipedia has a list of many of the spells; search for "Harry Potter Spells". Several fansites also list the known spells; for example, the Harry Potter Lexicon (hp-lexicon.org). Please note that none of the spells work in real life; they are part of a fantasy story. Also, not all details about each of the spells are known; the sites mentioned, and others, only list details that appear in the books, for example, the exact words to say, if it has been mentioned in the books.