The form of a word that is chosen to serve as the lemma is usually the least marked form, but there are several exceptions, such as, for several languages, the use of the infinitive for verbs.
For English, the citation form of a noun is the singular: e.g., mouse rather than mice. For multi-word lexemes that contain possessive adjectives or reflexive pronouns, the citation form uses a form of the indefinite pronoun one: e.g., do one's best, perjure oneself. In languages with grammatical gender, the citation form of regular adjectives and nouns is usually the masculine singular. If the language additionally has cases, the citation form is often the masculine singular nominative.
For many languages, the citation form of a verb is the infinitive: French aller, German gehen, Spanish ir. For English this usually coincides with the uninflected, least marked form of the verb (that is, "run", not "runs" or "running"); the present tense is used for some defective verbs (shall, can, and must have only the one form). For Latin, Ancient Greek, and Modern Greek, however, the first person singular present tense is traditionally used, although some modern dictionaries use the infinitive instead. (For contracted verbs in Ancient Greek, an uncontracted first person singular present tense is used to reveal the contract vowel: φιλέω philéō for φιλῶ philō "I love" ; ἀγαπάω agapáō for ἀγαπῶ agapō "I love" ). Finnish dictionaries list verbs not under the verb root but under the first infinitive, marked with -(t)a, -(t)ä.
For Japanese, the non-past (present and future) tense is used. For Arabic, which has no infinitives, the third-person singular masculine of the past tense is the least-marked form, and is used for entries in modern dictionaries. In older dictionaries, which are still commonly used today, the triliteral of the word, either a verb or a noun, is used. Hebrew often uses the third-person masculine perfect, e.g., ברא bara' create, כפר kaphar deny. Georgian uses the verbal noun. For Korean, -da is attached to the stem.
In Irish, words are highly inflected depending on their case (genitive, nominative, dative and vocative); they are also inflected on their place within a sentence because of initial mutations. The noun cainteoir, the lemma for the noun meaning "speaker", has a variety of forms: chainteoir, gcainteoir, cainteora, chainteora, cainteoirí, chainteoirí and gcainteoirí.
Some phrases are cited in a sort of lemma, e.g., Carthago delenda est (literally, "Carthage must be destroyed") is a common way of citing Cato, although what he said was nearer to Ceterum censeo Carthaginem esse delendam ("As to the rest, I hold that Carthage must be destroyed").
In a dictionary, the lemma "go" represents the inflected forms "go", "goes", "going", "went", and "gone". The relationship between an inflected form and its lemma is usually denoted by an angle bracket, e.g., "went" < "go". The disadvantage of such simplifications is, of course, the inability to look up a declined or conjugated form of the word, although some dictionaries, like Webster's, will list "went". Multilingual dictionaries vary in how they deal with this issue: the Langenscheidt dictionary of German does not list ging (< gehen); the Cassell does.