Before proceeding directly

Before proceeding directly to the analysis of the question, it is necessary to understand the basic concepts, namely what the American version of English is, briefly highlight its main differences from British English and its characteristics, as well as understand what borrowings mean in the language, what they are and what they are caused by. In addition, it is important to clarify the concept of slang.
First of all, American English is the version of English that has developed, as it can be easily understood, on the territory of the United States of America. It was brought to these territories by British, mostly English, colonists, in the seventeenth and eighteenth centuries, and since then has begun to actively develop and change, having differences and different characteristics in many States. In many States, the linguistic norms of the language are prescribed in educational standards, but, nevertheless, American English, like English, is not legally fixed as an official language.
As with many, if not all, languages in the world, the lexical, grammatical, and phonetic components of the American version of English were influenced by other languages, mostly European. Among them, of course, British English stands out most clearly as the original, Spanish, which influenced the vocabulary not only directly, but also indirectly - for example, a huge number of words were created that imitate Spanish by the type of their formation, Gallic languages, and most vividly - French, which influenced the frequency of consumption of its so-called "clerical" words and some word formation processes, as well as Germanic languages, whose role, however, is not very noticeable against the general background and is reduced more to the sound of individual words, which also lost most of their similarity to German over time.
It is also certain that American English also has dialects. However, they all have more or less certain characteristics. One of the most prominent features of American English is the pronunciation of sounds, which stands out either in too clear sharp pronunciation, or in softening, as well as in intonation. Vowel slips and palatalization are also quite noticeable. This is followed by spelling differences originating from the work of Noah Webster, and grammatical differences, mainly expressed in the choice of modal verbs and tenses for expressing thought.
The explanation of cases of borrowing, as well as their causes, are generally common to the British and American versions of English. So, the most obvious reason for borrowing both in English and in world languages in general, is the migration of peoples, or rather the transition of indigenous representatives of the land to other lands and the mixing of the source language with the language of the new location, or, conversely, migration of other peoples into the territory of discussing language with further assimilation and introduction of distinctive elements in a language. Also among the reasons for borrowing can be identified dissatisfaction with the lexical set of users of the language and the inability to adequately convey a particular idea.
The reason for borrowing and the appearance of slang in the American version of English may also be a kind of protest of young people against "prim" English and the desire to bring individuality to it.
And, also similar to other languages, there are several types of word borrowing, including transcription, i.e. borrowing a dictionary unit with its sound form, transliteration, which implies borrowing a dictionary unit by transmitting it with the letters of the receiving language, and calque, which consists in borrowing words by translating their parts.
The number and scale of slang distribution increases most strongly during any political, social and other events that massively affect society, since it is society that is acutely aware of the need to express its own attitude to what is happening and powerlessness in terms of its expression.
There are many examples of how words that were previously treated by society as slang and did not attach to it the meaning inherent in "dictionary words", firmly entered the vocabulary of the nation, getting rid of the "slang" color. So, for example, it was with the words "bus", "lunch" and others.
According to Flexner, one of the compilers of the Dictionary of English slang, for 600 thousand words in English there are 45 thousand slang words, and if we talk about the scale of the vocabulary of individual people, then for 20 thousand lexical stock there are about 2 thousand "fashion words".
Now, what was once considered to belong only to certain people, in the minds of some - even the lower strata of society, becomes the property of the speech of a huge number of people, including businessmen, public figures, and even politicians. Slang becomes a convenient tool for expressing thoughts and a way to both approach the people and express their involvement in them.
The following are examples of American slang, they can be surprising, since many of these words have long been perceived as part of the "official" language.
Awesome.This word has a whole range of shades, usually expresses admiration, shock, surprise, but can also be used to express agreement, sub-conviction. Of course, it can be used in an ironic context, but this exception applies to many words.
Cool.
It has the meaning "cool", although, of course, its more traditional meaning is "cold", but this is a vivid example of how the slang meaning of the word replaces its traditional meaning.
To chill out.It has the meaning "rest, relax", and, as an illustration of the meaning of the word, "out" is often omitted, which does not affect the meaning. It is quite common and is used in other languages in an adapted form.
It can also have the imperative meaning "calm down!" if the opponent is too nervous or misbehaves.
Babe.A very, very vivid and characteristic example of slang. Indicates a girl that the speaker finds attractive. It often has an obscene and vulgar connotation. However, it is widely distributed outside the country in an unchanged or adapted form.
To have a crush on somebody.This phrase has the meaning of "falling in love" with a person, is actively used by young people and has also gone beyond the country, becoming popular in other languages.
To dump somebody.In contrast to the previous expression, it has the meaning of "break up with someone", and in a rather sharp sense, "break up with someone".
Ex.In continuation of the subject of relationships, this word has the meaning "ex", refers to the ex-boyfriend or girlfriend, and also, with the addition of husband or wife, is used in relation to the ex-husband and wife.
Geek.A word that denotes a person who is quite passionate about something, and sometimes it can have a rather negative or offensive meaning, like "nerd". It is also used in transcribed form in other languages.
Epic fail.A fairly well-known phrase that denotes a failure in any business, most often it is used in a hyperbolized meaning to increase the effect produced.
Special attention is must be given to Black English. Black English has been the source of a significant number of borrowings of lexical units in the American version of English for many years. It is largely due to him, the influence of African-American culture and a special imaginative reinterpretation of words, the American version of English became so different from the British English version that it was considered as an independent language at the end of the nineteenth century.
Of course, it is necessary to remember that many units of Black English were originally borrowed from traditional English, and therefore their assimilation in American English is very relative and the process of borrowing and creating a characteristic, ethnically colored slang largely consists only in adapting already modified words of traditional English. The reasons for mutual borrowing from Black English and American English are the same desire to find more adequate and equivalent ways of expressing thoughts, the desire to express one's own individuality or emphasize national characteristics by introducing lexemes characteristic of certain ethnics into speech.
There has also been a widespread tendency to borrow words from the British version of the English language, sometimes with the opposite meaning to the intended meaning. Most often, this is done either out of a desire to increase social prestige by showing the level of language proficiency, but also because of a desire to add ironic humor to certain phrases. Borrowing has occurred and is happening completely, more often only the sound is replaced. Unfortunately, there is another reason for borrowing. Behind it lies a long and sad history of the people, their oppression, hard work and deprivation. The following examples illustrate these reasons.
Cirb; downhome; pad – home, hearth;
Blood; (soul) brother; crew; deep; dog; homey(- blood; (soul) brother; crew; deep; dog; homey, niggar, peeps, partner, sidecick, sister, squeeze, young-used to refer to a friend, friendly African-American, African-American
Kicker, devil, peckerwood, pig, silk, vanilla- so white people called
Euro-American laws, mallet, the man. folks - used relative to police
officersCheese, cheddar, cream, green, snaps - used to refer to money
To cruise - drive at low speed, exposing the car
To front - try to start a quarrel
Hit, jammin' - a particularly successful piece of music
The following examples illustrate the borrowing of book vocabulary with often changed spelling due to the high status of literary English.
bourgeoisie - interested only in material welfare.
communicate - conduct a conversation
solid - yes, well
confront - resist
knowledgeable - ready.
The following are examples of slang used most often in situations where there is a state of affect.
Bump that! - Do not pay attention!
I'm gonna steal yo! - get it Now!
My Gag! - Sorry! (in an ironic sense)
If earlier Black English only borrowed some lexical units of American and British English, then later it becomes a source of borrowings.
The first reason is the lack of appropriate names for certain phenomena, most often related to music. Examples are the words blues, boogie, break, solid, rap, scat, jive, punk. chart, break-dancing.
The second reason is the need for synonyms for affective words. For example, the special vocabulary of the criminal case includes such words as conga, gungeon, and gunny.
The third reason is the increase in the prestige of black English in some circles. Therefore, the literary English language includes such words as boom-box, that is, a large portable tape recorder, bones, which means dominoes, to bounce-to leave, the hawk, meaning cold wind, to high five, which means to say Hello ("give five").
Specific slang is a rather difficult topic for many people to understand. His lack of understanding sometimes leads to cross-cultural conflicts, which are sometimes very difficult to resolve. However, there are currently active attempts to popularize "small" slang groups, which allows more and more people to better understand their specific vocabulary.
In the course of work were considered the concept of the American English language, his description and traits, are considered the concept of slang and its causes, investigated the phenomenon of borrowing and their causes, as well as concrete examples.