Eth

Eth (/ɛð/, uppercase: Ð, lowercase: ð; also spelled edh or eð) is a letter used in Old English, Middle English, Icelandic, Faroese (in which it is called edd), and Elfdalian. It was also used in Scandinavia during the Middle Ages but was subsequently replaced with dh and later d. It is often transliterated as d (and d- is rarely used as a mnemonic). The lowercase version has been adopted to represent a voiced dental fricative in the International Phonetic Alphabet.

The letter originated in Irish writing as a d with a cross-stroke added. The lowercase version has retained the curved shape of a medieval scribe's d, which d itself in general has not.

In Old English, ð (referred to as ðæt by the Anglo-Saxons) was used interchangeably with þ (thorn) to represent the Old English dental fricative /θ/, which could manifest as either voiceless (and thus like the th in Modern English think) or voiced (and thus like the th of Modern English that) depending on where it appeared in a word or utterance. The letter ð was used throughout the Anglo-Saxon era but gradually fell out of use in Middle English, practically disappearing altogether by 1300;þ survived longer, ultimately being replaced by the digraph th.

Eth-

eth- is a chemical prefix. It was extracted from "ethyl". It serves as the number 2 when counting axial atoms in forming names of organic compounds.

English verbs

Verbs constitute one of the main word classes in the English language. Like other types of words in the language, English verbs are not heavily inflected. Most combinations of tense, aspect, mood and voice are expressed periphrastically, using constructions with auxiliary verbs and modal verbs.

Generally, the only inflected forms of an English verb are a third person singular present tense form in -s, a past tense (also called preterite), a past participle (which may be the same as the past tense), and a form in -ing that serves as a present participle and gerund. Most verbs inflect in a simple regular fashion, although there are about 200 irregular verbs; the irregularity in nearly all cases concerns the past tense and past participle forms. The copula verb be has a larger number of different inflected forms, and is highly irregular.

For details of the uses of particular verb tenses and other forms, see the article Uses of English verb forms. For certain other specific topics, see the articles listed in the box to the right.