# principal part
## English
### Etymology

Calque of Late Latin principālis pars

### Noun

principal part (plural principal parts)
* (grammar, usually in the plural):
** (obsolete) Any one of however many parts of speech regarded as the most fundamental or indispensable.
    Holonym: part of speech
*** (rare) The noun, verb, or adverb.
**** 1677, John Clarke, The Second Praxis Dialogical of the Latine Syntax, Tranſlated Grammatically into Engliſh, for the uſe and benefit of Grammar Schools. (pages 189–246), in Dux Grammaticus Tyronem Scholaſticum. Ad rectam Orthographiam, Syntaxin, & Proſodiam Dirigens., seventh edition (overall work in Latin and English), London: Edward Thomas, The Rules of Conſtruction., pages 239–240:For the underſtanding of this, we muſt conceive the order of Nature. For whatſoever we find in the whole World, are either Things, Actions, or Circumſtances: The Things are known before their Actions, and Actions firſt to be conſidered, before the Circumſtances. Hence it is that the Speech that is ordained of God in Man, to declare the Conceits of his Mind to others hath properly three principal parts, viz. Nouns to name things, Verbs to ſhew Actions, and Adverbs to note Circumſtances.
*** The noun or the verb.
**** 1678, “A. B. Philo-Muſ.”, Rudiments of the Latine Grammar, London: Dorman Newman, Of SYNTAX., page 33:The principal parts of a ſentence are words, without which abſolutely no ſentence can be made. And are both a ſubſtantive ſignifying that, which doeth, ſuffereth, or is, and a verb ſignifying to do, to ſuffer, or to be.
**** ibidem, page 34:
    The leſs principal parts of a ſentence are words, which more fill up a ſentence, already made up of the principal parts. And are both adjectives and ſubſtantives.
**** 1687, Guy Miege, The Great French Dictionary, The Second Part, London: printed by John Redmayne for Thomas Basset, s.v. “Verb”:Nouns and Verbs are the two principal Parts of Speech, les Noms & les Verbes ſont les deux principales Parties d’Oraiſon.
** Any of the forms of a word which contain its stem(s) in the simplest form, or such a form that, when taken with all the other principal parts (showing various inflections), allows the entire paradigm to be derived.
    Holonyms: declension, conjugation
*** 1714, Thomas Sheridan, An Eaſy Introduction of Grammar in Engliſh. For the Underſtanding of the Latin Tongue. Compil’d not only for the Eaſe and Encouragement of Youth, but alſo for their Moral Improvement; having the Syntaxis Examples gather’d from the Choiceſt Pieces of the beſt Authors. To which is added, A Compendious Method of Variation, and Elegant Diſpoſition of Latin., Dublin: Printed by Daniel Tompson in Cole’s-Alley, Castle-Street, for the Author., The Preface., page vi:In the Verbs, I have made ſeveral Alterations from the common Form, which I hope will be found much for the eaſe and advantage of the Learner; for I have not only made them more Perſpicuous as to their ſeveral Kinds, Moods, and Tenſes, but I have alſo ſet down a Scheme of Formation, in which the Changes made of the principal Parts, i. e. Preſent, Perfect-Tenſe and firſt Supine, are diſtinguiſh’d by a ſmaller Letter, and after them the four Conjugations at length, according to the ſame Method.
*** ibidem, An Introduction to the Eight Parts of Speech., Of a Verb., page 63:
    There are Three Principal Parts of a Verb, from which the reſt are Form’d, the Preſent-Tenſe, Perfect-Tenſe, and the Firſt Supine.
*** 1714, Thomas Ruddiman, The Rudiments of the Latin Tongue, or A plain and eaſy Introduction to Latin Grammar; Wherein the Principles of the Language are Methodically digeſted both in Engliſh and Latin: with Uſeful Notes and Obſervations, explaining the Terms of Grammar, and further improving its Rules. (overall work in English and Latin), Edinburgh: Robert Freebairn, part II: De Dictionibus. Of Woꝛds., chapter iii: De Verbo. Of Verb., page 50:In every complete Verb there are commonly four PRINCIPAL PARTS, viz. The Preſent of the Indicative in O, the Preterite or Perfect in I, the firſt Supine in UM, and the Preſent of the Infinitive in RE. The firſt (which is therefore called the THEME or Root of the Verb) gives Origin to the whole Verb either mediately or immediately. The Preterite, the firſt Supine, and the Preſent of the Infinitive come from it immediately, and all the reſt from them; except the Future of the Indicative in am, and the Preſent of the Subjunctive in em, which by this Scheme are alſo formed immediately from the Preſent in O.
*** 1870, March, Comp. Gram. Ags. Lang., page 78:The Principal Parts [of a verb] are the present infinitive, the imperfect indicative first person, and the passive participle.
*** For more quotations using this term, see Citations:principal part.
* (mathematics) A polynomial approximation of a power series, made up of monomials whose indices lie in the Newton diagram of the power series and which occur with the same coefficients as in the original power series.
* (mathematics) The portion of a Laurent series that has negative exponents.
* Used other than figuratively or idiomatically: see principal,‎ part.

#### Usage notes

* In Latin grammar: the two principal parts of a noun are the singular nominative and the singular genitive; the three of an adjective are the masculine, the feminine, and the neuter singular nominatives; and the four of a verb are the first-person singular present active indicative, the 1st-pers. sg. perfect act. ind., the pres. act. infinitive, and the supine (or, in the case of deponent verbs, the three are the 1st-pers. sg. pres. act. ind., the pres. act. inf., and the perf. act. participle).
* In the grammars of most Germanic languages: the three principal parts of verbs are the present infinitive, the first-person singular imperfect indicative, and the passive participle.
* In English grammar: the two principal parts of a noun are the singular and the plural; the three of an adjective are the positive, the comparative, and the superlative; and the three of a verb are the infinitive, the simple past, and the past participle.

#### See also

* (form of a word): lexeme

### References

* A New English Dictionary on Historical Principles (1st ed.), volume VII (O–P, ed. James Augustus Henry Murray, 1909), § 2 (P), page 499/1 s.v. “Part, sb. (adv.)”, sense 19.b

### Further reading

* principal part (grammar) on Wikipedia.Wikipedia
* principal part (mathematics) on Wikipedia.Wikipedia