Mandarin is a tonal language. The phonetic representation of the language, pinyin, indicates which tone to use … usually. Certain combinations of syllables cause the tones to change. A good example is 你好 means hello. In the dictionary it is written nǐhǎo (3rd-3rd), but it is spoken níhǎo (2nd-3rd).
Most text books expect students to memorize these rules, so they print all words with dictionary tone. Effective Chinese, however, prints Mandarin with spoken tone, because it is difficult for beginners to remember. Our materials will indicate the changed tone by using a slightly lighter font color.