A prefix is a group of letters placed before the root of a word. For example, the word “unhappy” consists of the prefix “un-” [which means “not”] combined with the root (or stem) word “happy”; the word “unhappy” means “not happy.” A suffix is a string of letters that go at the end of a root word, changing or adding to its meaning. Suffixes can show if a word is a noun, an adjective, an adverb or a verb. The suffixes -er and -est are also used to form the comparative and superlative forms of adjectives and some adverbs. Portuguese...Sufixo é uma letra ou um grupo de letras que é normalmente adicionado no final das palavras, para alterar a forma como uma palavra se encaixa numa frase gramaticalmente. Russian...Суффикс – это буква или группа букв, которые обычно добавляются в конец слова, чтобы изменить способ грамматического вставки слова в предложение. Chinese..后缀是一个字母或一组字母，通常加在单词的末尾，以改变一个单词在语法上与句子的配合方式。 Japanese...Suffix（サフィックス）とは、通常、単語の末尾に付加される文字または文字群のことで、 文法的に単語が文に収まる方法を変えるためのものです。