Common nouns refer to general categories of things, people, and abstract concepts. "People" is the plural noun for human beings in general. "Year" refers to a period of 365 days (or 366 in a leap year). "Day" refers to a 24-hour period. "Time" can mean an indefinite duration or a specific moment. "Thing" is a general noun for an object, item, or matter. "Way" can mean a road, method, or manner. These nouns appear so frequently that they have become almost function-like in everyday English.
Common adjectives describe qualities and quantities. "Good" means of high quality, pleasant, or moral. "New" means not existing before or recently made. "Long" means great in length or duration. "Many" is used with countable nouns to mean a large number. "Only" can function as an adjective or adverb meaning "solely" or "merely." "Other" means different or additional. Adjectives typically come before the noun they modify ("a good book") or after a linking verb ("the book is good").
Adverbs modify verbs, adjectives, or other adverbs, adding information about manner, time, place, or degree. "Just" means "merely" or "recently." "Also" means "in addition" or "too." "Still" indicates that something is continuing or without movement. "Then" refers to a past time or what comes next. "Now" means at the present time. "Here" means in or to this place, while "there" can mean in or at that place, or introduce existence ("there is/are"). "Even" emphasizes surprise ("even I knew that") or can be an adjective meaning flat or equal. "Very" is an intensifier meaning to a high degree. "Well" is the adverb form of "good," meaning in a satisfactory manner. "Back" is an adverb meaning toward the rear, or a noun referring to the posterior. "Why" asks about reason or purpose. Numbers include "two" (the cardinal number 2) and "first" (the ordinal number 1, meaning initial).