... in This does not always have a negative meaning – often it gives the idea of inside or into,e.g. internal, insert, income. Verb prefixes: un- and dis These prefixes have two meanings. ... for using the articles? The indefinite article (a / an) is used with singular countable nouns referring to a non-unique item in general: • separate objects, people, ideas, etc. singular ... order to convey my points clearly to the reader? 66 Grammar Six excellent career fields within mechanical engineering technology are heating, ventilating, and air conditioning (HVAC); mechanical...