A checked tone, commonly known by the Chinese calque entering tone, is one of the four syllable types in the phonology in Middle Chinese. Although usually translated as "tone", a checked tone is not a tone in the phonetic sense but rather a syllable that ends in a stop consonant or a glottal stop. Separating the checked tone allows -p, -t, and -k to be treated as allophones of -m, -n, and -ng, respectively, since they are in complementary distribution. Stops appear only in the checked tone, and nasals appear only in the other tones. Because of the origin of tone in Chinese, the number of tones found in such syllables is smaller than the number of tones in other syllables. In Chinese phonetics, they have traditionally been counted separately.
