In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can carry grammatical information (inflectional endings) or lexical information (derivational/lexical suffixes). Inflection changes the grammatical properties of a word within its syntactic category. Derivational suffixes fall into two categories: class-changing derivation and class-maintaining derivation.
Particularly in the study of Semitic languages, suffixes are called affirmatives, as they can alter the form of the words. In Indo-European studies, a distinction is made between suffixes and endings (see Proto-Indo-European root).
A word-final segment that is somewhere between a free morpheme and a bound morpheme is known as a suffixoid or a semi-suffix (e.g., English -like or German -freundlich "friendly").
Inflection changes the grammatical properties of a word within its syntactic category. In several languages, this is realized by an inflectional suffix, also known as desinence. In the example:
the suffix -d inflects the root-word fade to indicate past participle.
Inflectional suffixes do not change the word class of the word after the inflection. Inflectional suffixes in Modern English include:
Derivational suffixes can be divided into two categories: class-changing derivation and class-maintaining derivation. In English, they include
A suffix will often change the stress or accent pattern of a multi-syllable word, altering the phoneme pattern of the root word even if the root's morphology does not change.  An example is the difference between "photograph" and "photography." In this case, the "-y" ending governs the stress pattern, causing the primary stress to shift from the first syllable ("pho-") to the antepenultimate ("-to-"). The unaccented syllables have their ordinary vowel sound changed to a schwa. This can be a particular problem for dyslexics, affecting their phonemic awareness,  as well as a hurdle for non-native speakers.
Many synthetic languages—Czech, German, Finnish, Latin, Hungarian, Russian, Turkish, etc.—use many endings.