In linguistics, grammatical conjugation is the creation of derived forms of a verb from the word root by inflection (regular alteration according to rules of grammar). Conjugation may be affected by person, number, gender, tense, mood, voice, grammatical aspect, or other language-specific factors. When a verb is used to function as the action done by a subject, the verb must be conjugated in most languages. Usually a mostly unconjugated form also exists, called the infinitive. A table giving all the conjugated variants of a verb in a grammar of some language is called a conjugation table.

A second use of the term is the grouping of all the verbs that are conjugated similarly in a particular language into conjugations. This is the sense in which teachers say that Latin has four conjugations of verbs. This categorisation tells us that we can conjugate any regular Latin verb to any person, number, tense, mood, and voice if we know which conjugation group it belongs to and some key forms called principal parts. (Latin does not conjugate for gender or aspect.)

Examples of conjugation

Conjugation is very extensive in most Indo-European languages. Here is a sample conjugation of the English verb to be and its Latin, French, German, Spanish, Brazilian Portuguese, and Swedish equivalents—esse, être, sein, ser, ser, and vara, respectively. Notice the similarities between English, German, and Swedish on the one hand and French, Spanish, Brazilian Portuguese and Latin on the other; notice also that, where the infinitive is concerned, only English and Swedish are very much divergent from the rest of the major European languages, all of which lends important clues as to the philology of English.

To be in several Indo-European languages. Except for the infinitive, which is in the present active form, all the verbs listed are in the present indicative active. The appropriate pronoun is included in most of the examples.

Form / Person	English	Latin	French	German	Spanish	Brazilian Portuguese	Swedish
infinitive	to be	esse	être	sein	ser	ser	vara
1st singular	I am	(ego) sum	je suis	ich bin	yo soy	eu sou	jag är
2nd singular	you are	(tu) es	tu es	du bist	tu eres / usted es	tu és / você é	du är
3rd singular	he, she, or it is	(is/ea/id) est	il / elle est	er / sie / es ist	el / ella / eso es	ele / ela / isto é	han / hon / den är
1st plural	we are	(nos) sumus	nous sommes	wir sind	nosotros(as) somos	nós somos	vi är
2nd plural	you are	(vos) estis	vous êtes	ihr seid	vosotros(as) sois / ustedes son	vós sóis	ni är
3rd plural	they are	(ei/eae/ea) sunt	ils / elles sont	sie sind	ellos(as) son	eles são	de är

Related topics

The grammatical conjugation of an irregular verb forms a model for a genre of joke called the self-serving conjugation. This satirizes the fashion in which violations of the Categorical Imperative may be cloaked in verbal obfuscation. For example: I delegate effectively, you play politics, he is in violation of his service-level agreement.