Features of the diachronic approach:
all periods in the history of the development of a language are taken – vertical study;
only one level of a language is studied (phonetics or grammar or lexicon);
only one functional variety of a language is studied (e.g. Standard English).
Features of the synchronic approach:
a certain period in the history of the development of a language is taken (fixed time boundaries) – horizontal study;
each level of a language is studied (phonetics, grammar, lexicon);
different functional varieties of a language are studied (different dialects of this period).
