We learn from examples like these that a word's lexical category can be identified only by looking to see how it is used in a sentence.Thus, while we endeavored to list exemplars from various lexical categories in Sections 5.3.2 and 5.3.3, doing so was rather misleading. Only a sentence's structure can reveal the lexical category of the words used in it. As a final note, it is interesting that in English, many nouns can easily be turned into verbs without any morphological alteration at all. This is not necessarily true of all (or even of most) languages. Thus you must be extremely careful when assigning lexical categories to words: the best way to identify a word's lexical category is to look carefully at how it functions in a sentence.