Words with similar roots and common parts are called one-root. It is easy to guess that this common part should be the root (or one of the roots, if the word is complex). Therefore, first of all, it is necessary to understand what the root is. The rule of the Russian language for Grade 1 says that the root is the common part of related words, which contains their basic meaning.
Like a tree, the word "grows" from the root.
The ability to correctly select related words (they are also cognate) allows us to write correctly. This applies to such spelling as unstressed vowel in the root (for example, in the word "river" unstressed "e" checks the root word "river", in which "e" is stressed).
Children often confuse family ties with different forms of the same word. So, for the word “mouse” - “mouse” is a one-root word, and “mice” is another form of the same. Forms of a word change with a change in its ending, and related words are formed using prefixes and suffixes. Moreover, consoles can change the meaning of the word even to the opposite. For example, the antonyms of Arrival and Departure are at the same time root words.
Another common mistake in the definition of cognate words is to take for related words those whose root coincides in spelling and sound, but not in meaning. Such roots are called homonymous. For example, in the words “wear”, “tray”, “porter” - the root -nos-, in the words “nose”, “sock”, “nose bridge” - also -nos-, but there is nothing common in their meanings. Words with homonymous roots are not root words. The opposite situation can be observed in words very close in meaning, but not having a common root. For example: a dog - a puppy, a horse - a foal, etc. The Russian language is not only rich, but also very unpredictable!
Odnokorenny words can be as one part of speech, or different (run, runner, runner are nouns; run, run - verbs; run, runaway - adjectives; runner - communion).
An interesting point in word formation is the alternation of sounds in the roots of related words, moreover, both vowels (dawn - dawns, hang - hung), and consonants (friend-friend-friend, dry-dry - dry). Variants are possible when consonants alternate with combinations of consonants (drive - driving, catching - catching), and vowels with a "zero sound", the so-called fluent vowel (father - father, sleep - sleep).
A root word can have two or more roots. Such words are called complex. In this case, one root will be related, and the other will serve as the basis for the formation of a new word in meaning. For example: greenery is evergreen, earth is a plowman, electricity is a hydroelectric power station.
All related words, ordered in relation to their derivative, together form a word-building nest. At the base of the nest is a vertex (source word), from which derivatives of single-root words are formed. Examples: singing - singer, singing - singing - singing; old - get old - get out of date - obsolete. A word-building nest can be weakly expanded (up to two derivatives) and strongly expanded (apex and more than three derivatives). An example of a strongly deployed nest is the one-root word for the word “house”: house, house, homemaker, house, house, house, home, home, householder, homeless, homebody, homeowner, homeowner, home economics, home building, house building, orphanage, madhouse.
Now you know what a root word is!