I hate to tell you this, but your english teacher is a lying liberal bitch that is twisting grammar rules in order to suit her biased agenda. The ammendment breaks down into two parts.
1. A well regulated militia being necessary to the security of a free state,
The proper explanation of this is as a preparatory clause. It explains the reason for the main point.
2. The right of the people to keep and bear arms shall not be infringed.
This is the main statement. The what behind the why of the preparatory clause. Right is the subject. Infringe is the verb. Shall not be is the adverbial restricting infringe. Keep and bear arms define the right being mentioned.
Because there may be a time in which we must quickly establish a well functioning (check definitions of regulated. Ever hear of a regulator clock?) militia, we want everyone to be able to handle firearms effectively. The best way is for them to be allowed to have personal arms with which they can become familiar with usage thereof.
Let me make an example of the original drivers license laws.
An unsafe driver being a hazard to the community, all drivers of motor vehicles shall be licensed.
This states that every one that drives a car must have a license "because" unsafe drivers are a hazard. This is the same format as the second amendment.
Another point is that the preparatory clause does not stand alone. In order to be a sentence, it requires a subject and verb. Militia is the subject, but there is no verb (adverbs don't count in making a sentence complete) Being is an adverb as this sentence is formed. Try seperating the two and it becomes obvious. A well regulated militia being necessary to the security of a free state, ... WHAT!?!?!?!? However, the right of the people to keep and bear arms shall not be infringed. Does stand on its own merit.
Also, your punctuation is wrong. There is only one comma in the ammendment. It is between state and the. There is no comma after arms.
Tell your teacher that she is an incompetent, lying bitch. I couldn't learn squat about grammar in public schools or college because of the gross incompetence of the teachers. I learned proper English grammar by studying Japanese in the Army. To prove her incompetence, I give you my name. Make sure you spell it correctly and ask her to read it to you. It is Floyd Shown. With an O, not an A. My last name is the past participle of the verb Show. As in has, have, or had shown. When she reads it as shAwn you can put her in her place. (That one I learned in the third grade because throughout my entire educational career, not one english teacher ever pronounced it right without first being corrected.
Now, if she tries the "people" means the state, ask her to read the preamble. The first three words "We the People". Does this then limit the second ammendment right to the signatories? No, the signatories represented all the citizens of their districts and the bill of rights was written for all the citizens of their districts. the first ten ammendments are meant for each and every citizen of the United States. They are not a right of the state, or of the federal government. (Oh yeah, tell that liberal bitch, that those rights do [b] [r] NOT [/b] [/r] extend to non citizens such as illegal aliens or the prisoners held in Guantanamo Bay. Only to natural or naturalized citizens of this country.
Sorry for the lecture, but I get really pissed when the liberals try to twist the language to their own gains. "depends on what the definition of is is" This from someone that knows and respects the proper forms of our language and can put any public and most college english teachers totally to shame.