Words may be used for friendship, but there are also four means of fighting which may be undertaken by words: negotiation, persuasion, dissuasion, and attack.
Negotiation is undertaken with five strategies: praise (of the opponent), establishing and building upon mutual relationships (co-ordination, mutual society), establishing and building upon co-operations, identification and discovery of individual and shared interests, and pro-spection of new interests.
Inducing an opponent toward your praise is possible by sharing their values, such as family, character, occupation, conduct, belief, learning, property, etc. Inducing co-ordination is possible by socializing with an opponent within their structures of family, schools, religion, friendships, business, etc. Inducing the help of an opponent is possible by being helpful, necessary and useful to them. Inducing pro-spection of an opponent is possible by proposal and bidding, just as asking and offering induces an opponent toward discovering shared interests or respecting individual interests.
Persuasion is undertaken by offering what is desired or either withholding or preventing against what is feared; dissuasion is undertaken by offering what is feared, or either withholding or preventing/obstructing what is desired. Persuasion is the means of agreement and unification, dissuasion is the means of dissention and fracture.
Attack is undertaken by destruction, deconstruction, harassment, taking or plundering: ideas, value, beliefs, reason, argument, identity, understanding, and other intangibles are formed through words, and remain subject to them.
In using words for friendship or fighting, one must avoid clumsiness, contradiction, repetition, bad grammar, wrong words, wrong connotation, incorrect gender, incorrect number, incorrect time, incorrect casing, poor construction or arrangement, wrong address, and other error. Paragraphs must be divided in suitable places to encourage understanding, and sentences joined into paragraphs to promote understanding. And special attention must be paid to the style: for the opponent's culture, caste, family, social rank, age, learning, occupation, property, character, relationships, as well as the time and place the words will be given and received can bring unintended consequence to words.