English grammar

English grammar is the structure of expressions in the English language. This includes the structure of words, phrases, clauses and sentences.

There are historical, social, cultural and regional variations of English. Divergences from the grammar described here occur in some dialects of English. This article describes a generalized present-day Standard English, the form of speech found in types of public discourse including broadcasting, education, entertainment, government, and news reporting, including both formal and informal speech. There are certain differences in grammar between the standard forms of British English, American English and Australian English, although these are inconspicuous compared with the lexical and pronunciation differences.

Word classes and phrases

Eight types of word ("word classes" or "parts of speech") are distinguished in English: nouns, determiners, pronouns, verbs, adjectives, adverbs, prepositions, and conjunctions. (Determiners, traditionally classified along with adjectives, have not always been regarded as a separate part of speech.) Interjections are another word class, but these are not described here as they do not form part of the clause and sentence structure of the language.

Planets beyond Neptune

Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and culminated at the start of the 20th with Percival Lowell's quest for Planet X. Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune, speculating that the gravity of a large unseen ninth planet could have perturbed Uranus enough to account for the irregularities.

Clyde Tombaugh's discovery of Pluto in 1930 appeared to validate Lowell's hypothesis, and Pluto was officially named the ninth planet. In 1978, Pluto was conclusively determined to be too small for its gravity to affect the giant planets, resulting in a brief search for a tenth planet. The search was largely abandoned in the early 1990s, when a study of measurements made by the Voyager 2 spacecraft found that the irregularities observed in Uranus's orbit were due to a slight overestimation of Neptune's mass. After 1992, the discovery of numerous small icy objects with similar or even wider orbits than Pluto led to a debate over whether Pluto should remain a planet, or whether it and its neighbours should, like the asteroids, be given their own separate classification. Although a number of the larger members of this group were initially described as planets, in 2006 the International Astronomical Union reclassified Pluto and its largest neighbours as dwarf planets, leaving Neptune the farthest known planet in the Solar System.

Age of Empires

Age of Empires is a series of personal computer games developed by Ensemble Studios and published by Microsoft Studios. The first title of the series was Age of Empires, released in 1997. Since then, seven titles and three spin-offs have been released. The titles are historical real-time strategy games, and their gameplay revolves around two main game modes: Single player and campaign. They competed with another popular strategy series, Civilization, and are set amidst historical events.

Age of Empires focused on events in Europe, Africa and Asia, spanning from the Stone Age to the Iron Age; the expansion game explored the formation and expansion of the Roman Empire. The sequel, Age of Empires II: The Age of Kings, was set in the Middle Ages, while its expansion focused partially on the Spanish conquest of Mexico. The subsequent three games of Age of Empires III explored the early modern period, when Europe was colonizing the Americas and several Asian nations were on the decline. The newest installment, Age of Empires Online, takes a different approach as a free-to-play online game utilizing Games for Windows Live. A spin-off game, Age of Mythology, was set in the same period as the original Age of Empires, but focused on mythological elements of Greek, Egyptian, and Norse mythology.