Since its inception four centuries ago, Spenser's diction has been scrutinized by scholars. Despite the enthusiasm the poet and his work received, Spenser's experimental diction was "largely condemned" before it received the acclaim it has today. Seventeenth century philologists such as Davenant considered Spenser's use of "obsolete language" as the "most vulgar accusation that is laid to his charge". Scholars have recently observed that the classical tradition tucked within The Faerie Queene is related to the problem of his diction because it "involves the principles of imitation and decorum". Despite these initial criticisms, Spenser is "now recognized as a conscious literary artist" and his language is deemed "the only fitting vehicle for his tone of thought and feelings". Spenser's use of language was widely contrasted to that of "free and unregulated" sixteenth century Shakespearian grammar. Spenser's style is standardized, lyrically sophisticated, and full of archaisms that give the poem an original taste. Sugden argues in The grammar of Spenser's Faerie Queene that the archaisms reside "chiefly in vocabulary, to a high degree in spelling, to some extent in the inflexions, and only slightly in the syntax".
Samuel Johnson also commented critically on Spenser's diction, with which he became intimately acquainted during his work on A Dictionary of the English Language, and "found it a useful source for obsolete and archaic words"; Johnson, however, mainly considered Spenser's (early) pastoral poems, a genre of which he was not particularly fond.
The diction and atmosphere of The Faerie Queene relied on much more than just Middle English; for instance, classical allusions and classical proper names abound—especially in the later books—and he coined some names based on Greek, such as "Poris" and "Phao lilly white." Classical material is also alluded to or reworked by Spenser, such as the rape of Lucretia, which was reworked into the story of the character Amavia in Book Two.
Spenser's language in The Faerie Queene, as in The Shepheardes Calender, is deliberately archaic, though the extent of this has been exaggerated by critics who follow Ben Jonson's dictum, that "in affecting the ancients Spenser writ no language." Allowing that Jonson's remark may only apply to the Calendar, Bruce Robert McElderry, Jr., states, after a detailed investigation of the FQ's diction, that Jonson's statement "is a skillful epigram; but it seriously misrepresents the truth if taken at anything like its face value." The number of archaisms used in the poem is not overwhelming—one source reports thirty-four in Canto I of Book I, that is, thirty-four words out of a total forty-two hundred words, less than one percent. According to McElderry, language does not account for the poem's archaic tone: "The subject-matter of The Faerie Queene is itself the most powerful factor in creating the impression of archaism."
Examples of medieval archaisms (in morphology and diction) include:
- Infinitive in –en: "Vewen," 1. 201, 'to view.'
- Prefix y- retained in participle: "Yclad", 1. 58, 254, "clad", "clothed".
- Adjective: "Combrous", 1. 203, "harassing", "troublesome".
- Verb: "Keepe", 1. 360, "heed", "give attention to".