Related words are words (lexemes) that have the same root but belonging to different parts of speech (white – white – white).

To find the root word, do not have good knowledge of word formation, the more that basic information on this section of the Russian language are taught in elementary school. However, it is useful to remember that the difference of related words is a set of postfixes (prefixes and postfixes (suffixes only). Words that have the same root, but differ only in the inflections (endings), related words are not, is a form of the same word: rivers and rivers.

In the Russian language there are several most common ways of word formation: prefix (added a prefix), suffix (suffix only), prefixal-suffixal (both the prefix and suffix). But for education cognate (related) words prefixed method is emphatically not suitable. Indeed, in this respect, there is a big difference, for example, in the words: run, run,-run, etc.

You need to remember about homonymous roots. So, the words of the waters-Jana and water-it will not be related, since the values of the roots in this case are different.

In addition, in the Russian language there is such a thing as conversions. A simple example: "he won – you lost", in which the words "won" and "lost" are precisely the converse, words expressing the same action, but in opposite directions. Here, in the foreground the semantics of words in context. So if you, say, offer to find cognate words in the sentence: "Karpov wanted to win against Kasparov, but Kasparov did not give in to him and not lost", think before giving a final answer.