an emotional greeting or exclamation (Huzzah, Alas). Interjections express strong feelings and emotions. Article (describes, limits)a grammatical marker of definiteness (the) or indefiniteness (a, an). The article is not always listed among the parts of speech. It is considered by some grammarians to be a type of adjective or sometimes the term 'determiner' (a broader class) is used. English words are not generally marked as belonging to one part of speech or another; this contrasts with many other European languages, which use inflection more extensively, meaning that a given word form can often be identified as belonging to a particular part of speech and having certain additional grammatical properties. In English, most words are uninflected, while the inflected endings that exist are mostly ambiguous: -ed may mark a verbal past tense, a participle or a fully adjectival form; -s may mark a plural noun, a possessive noun, or a present-tense verb form; -ing may mark a participle, gerund, or pure adjective or noun. Although -ly is a frequent adverb marker, some adverbs (e.g. tomorrow, fast, very) do not have that ending, while many adjectives do have it (e.g. friendly, ugly, lovely), as do occasional words in other parts of speech (e.g. jelly, fly, rely). Many English words can belong to more than one part of speech. Words like neigh, break, outlaw, laser, microwave, and telephone might all be either verbs or nouns. In certain circumstances, even words with primarily grammatical functions can be used as verbs or nouns, as in, "We must look to the hows and not just the whys." The process whereby a word comes to be used as a different part of speech is called conversion or zero derivation. Functional classification Linguists recognize that the above list of eight or nine word classes is drastically simplified. For example, "adverb" is to some extent a catch-all class that includes words with many different functions. Some have even argued that the most basic of category distinctions, that of nouns and verbs, is unfounded, or not applicable to certain languages. Modern linguists have proposed many different schemes whereby the words of English or other languages are placed into more specific categories and subcategories based on a more precise understanding of their grammatical functions. Common lexical category set defined by function may include the following (not all of them will necessarily be applicable in a given language): Categories that will usually