From the school program it is known that the words which are grammatical not connected with sentence parts are introduction (i.e. not connected on a way of management, coordination, an adjunction). By means of parenthesises the relation speaking to the introduced idea is expressed, the way of its registration is characterized. They have intonation of introductoriness which is expressed in faster pronouncing and depression of voice in comparison with the rest of the offer.
Morphologically such words are expressed or special parenthesises ("so", "please") or the words of different parts of speech, in case of their specific use ("fortunately", "opposite"). Parenthesises can belong also to all offer, and to its certain part. They mean: - additional expressional and emotional shades ("I, unfortunately, understood that I did"); - assessment of the reported fact telling degrees of reliability ("as a matter of fact", "needless to say", "without any doubt"); - assessment of the facts in terms of their ordinary ("as usual", "as usual"); - feelings of saying: joy, surprise, disappointment, a regret, etc. ("I, surprisingly, quickly understood about what the speech"); - the sequence of statement, communication of thoughts ("So, you do not want to cross the road"); - ways and methods of registration of thoughts, the expressional nature of a statement ("To admit to tell in any time there was no such storm here"); - streamlining of thoughts ("first", "secondly") and way of their registration ("in other words", "in a word"). A number of parenthetic clauses indicates a message source ("in terms of", "as is well-known"). In special group it is possible to select parenthesises which are turned to the reader or the interlocutor. Their purpose is drawing attention to the stated facts, suggestion of a certain relation to reported ("Make favor, listen that I will tell you"). Being not syntactically connected with sentence parts, often parenthesises carry out a constructive role and are necessary for its structure. The main sphere of their use – oral speech to which they give intonational expressiveness often meet in artistic speech, but not in book where preference is given to shorter introduction units. Offers with parenthesises are most often laconic, seldom are widespread.