Having come to the subject of free speech, I will make one important reminder. The above quote from the Bill of Rights starts with the words “Congress shall make no law”. The rights being guaranteed are with respect to government, NOT with respect to the whole world. Perhaps you have, like me, been exposed to someone who goes off on a rant about free speech, because they have not been heard to their satisfaction at some party or other. Your “rights” at a private party are granted by your host and he/she can revoke them at any time for any reason. We are only talking about government here.
The First Amendment starts with the word Congress. This is because the Bill of Rights was written for the U.S. Constitution which concerns ONLY the Federal government. By virtue of the 14th Amendment, the Bill of Rights was imposed by the Federal Government on the State Governments. From there it is extended further to include Counties, Cities and even Public Schools. You have no Free Speech rights in a private school.
When considering a Free Speech case, the court starts by asking the question “what kind of forum are we talking about?” They divide into public and private forums. A public forum is one that the public is invited to. Examples would be Planning Department Hearings, and PTA meetings. If it is not a Public Forum, you have no Free Speech rights. If it is a Public Forum, the next question is whether you are being subjected to Content-based discrimination, or ViewPoint-based discrimination. For example, a Planning Department Hearing will most likely have a pre-announced subject. Mr. X's request for a zoning exception on the parcel at 5th and Vine. You can't go to that hearing and expect to be heard with regard to some other subject you are upset about. Your comments will be suppressed under allowable Content-based discrimination. On the other hand if you go down to the park with your soapbox and start haranguing the crowd about what a poor job the mayor is doing, you have the full protection of the First Amendment. You are in a public forum with no set content specified. (See below for additional concerns re right to assemble) If a cop shows up and drives you off because you can't talk about the mayor that way, you have a legitimate Free Speech case.
As with freedom of religion, the various elements of the law have been expanded, and the right may be overridden by a more important societal need. In terms of expanded definitions, speech, according to the Supreme Court includes expressive actions.
For example, Armbands, Burning Crosses, and Exotic Dancing can all fall under the broad title of Speech. In the case of burning crosses, the court held they were a form of speech, and hence eligible for first amendment protection, but they declined the opportunity to assume, without other evidence, that they were intended as intimidating speech, and hence did not deny protection on the grounds of overriding societal need.
Abridging means not only preventing you from speaking, but also fining or punishing the fact that you spoke. Free Speech means not only that they can't stop you from saying what you believe, but also, they can not require you to say anything that you don't want to say. Furthermore, it is a violation of your free speech rights if the government pressures regulated entities to take discriminatory actions against you because of your speech.
Finally, your first amendment protection is lost if your speech is going to create an immediate and significant danger. For example shouting FIRE in a crowded theatre.
It is worth noting the interplay between free speech and liable. The government's interest in free speech is to foster an environment in which all political options and opinions get fully heard so that the citizens can make the most informed decisions concerning their government as is possible. It is NOT the government's interest to foster feuds. If the person you are degrading is a government official, and your criticisms are relevant to the public position held, the first amendment is there to protect you. On the other hand, if you are simply bad mouthing a neighbor who has no public position at all, your speech will likely NOT be protected and you may find yourself being sued for liable. If you intend to walk this line, you are best advised to get an attorney and discuss all the nitty gritty details.
Because I have given you so much general overview here, I am foregoing any specifc case review till the next screen, and just providing a video recap here.