It would not be illegal. Your first amendment rights only protect you from the government limiting your speech. School is not government.
Getting kicked out of school is not the same thing as being convicted of a crime but you're still kicked out.
This ends when cursing teachers begin, and sassing, talking back to teachers, also. These are not acceptable free speech.
L. E. Gant
Cursing and talking back is a matter of discipline, not free speech. If you have to curse and talk back, then you are breaking discipline rules,
Not happening - The First protects you from the Federal government . It isn't like the school is going to put you in jail or fine you, but punish you within the context of school. Schools, workplaces , coaches have the right o require civilized behavior as a condition of continued participation.
I love how you are selective on details. What are you on about, in talking back at the teacher, what if at the time they were attempting to provide knowledge to other students and your talking obstructed the teacher from teaching. How about the other students right to an education. What if a fellow students missed a point that you already know and later that same point was in an exam, other missed it because you would not let the teacher teach.
First amendment only guarantees you from censorship. It doesnt mean theres no reprocussions for exercising speech
Yes they can punish you. Read the last sentence here. see ** The issue of school speech or curricular speech as it relates to the First Amendment to the United States Constitution has been the center of controversy and litigation since the mid-20th century. The First Amendment's guarantee of freedom of speech applies to students in the public schools. In the landmark decision Tinker v. Des Moines Independent Community School District, the U.S. Supreme Court formally recognized that students do not "shed their constitutional rights to freedom of speech or expression at the schoolhouse gate". The core principles of Tinker remain unaltered, but are tempered by several important decisions, including Bethel School District v. Fraser, Hazelwood School District v. Kuhlmeier, and Morse v. Frederick. Despite respect for the legitimate educational interests of school officials, the Supreme Court has not abandoned Tinker; it continues to recognize the basis precept of Tinker that viewpoint-specific speech restrictions are an egregious violation of the First Amendment. In Rosenberger v. Rector and Visitors of the University of Virginia, the Supreme Court declared: "Discrimination against speech because of its message is presumed to be unconstitutional". Rosenberger held that denial of funds to a student organization on the sole basis that the funds were used to publish a religiously oriented student newspaper was an unconstitutional violation of the right of free speech guaranteed by the First Amendment. Accordingly, for other on-campus speech that is neither obscene, vulgar, lewd, indecent, or plainly offensive under Fraser nor school-sponsored under Hazelwood nor advocating illegal drugs at a school-sponsored event under Frederick, ** Tinker applies limiting the authority of schools to regulate the speech, whether on or off-campus, unless it would materially and substantially disrupt classwork and discipline in the school.** https://en.wikipedia.org/wiki/School_speech_(First_Amendment) Disruption The problem of disruption is perhaps the most fundamental issue addressed by the courts in student free speech cases. Offensiveness The second major question addressed by the courts is closely related to, but nevertheless distinct from, the question of disruption. This is the question of speech which is offensive to prevailing community standards by reason of being vulgar, lewd, or indecent speech. Courts have held that offensiveness is a question of whether speech is plainly offensive in terms of sexual content or implication, rather than simply expressing ideas and beliefs considered offensive by some or most students or members of the community. See Saxe v. State College Area School District. In Bethel School District v. Fraser, the Supreme Court recognized the special responsibility of the public schools to inculcate moral values and to teach students the boundaries of socially acceptable behavior. It therefore permitted a public school to discipline a student for making sexually suggestive remarks in an address to a school assembly, even though the remarks were not obscene in the traditional sense. The ability to regulate inappropriate speech has been found to be especially important in situations where the student speech may have the appearance of being sponsored or endorsed by the school. In Bethel, the Court held that the offensiveness test does not apply to off-campus speech. Impairing educational mission The third major area of concern addressed in student free speech cases is whether a particular instance of student speech may be viewed as impairing the school's ability to carry out its educational mission. This concern arises where the speech in question occurs in connection with a school-sponsored or school-controlled activity but is inconsistent with a legitimate pedagogical concern. In such circumstances, the United States Supreme Court has found that student speech may be regulated. For example, in Hazelwood School District v. Kuhlmeier, it held that a school may exercise control over the content of a student newspaper when it attempts to address issues of divorce and teenage pregnancy; in Morse v. Frederick, it permitted a school to exercise control over the words displayed on a large banner at a school-sponsored event, when those words convey a message promoting the use of illegal drugs. Pure speech One of these factors is whether the activity sought to be controlled is "pure speech", or sufficiently related to the expression of ideas to fall under the umbrella of the First Amendment. "Pure speech" does not need to involve words but is generally represented by symbols or actions. https://en.wikipedia.org/wiki/School_speech_(First_Amendment)#Disruption
Try doing that to a judge in a courtroom, and see what your free speech rights garner you.
Pascal the Gambler
Not illegal at all. You seem to think First Amendment means you can say whatever you want whenever you want. It does not. It means the government cannot prosecute you for your speech. That is all it means.