in the Chiang Mai dialect of Northern Thai: low-rising, low-falling, high-level with glottal stop, mid-level, high-falling, and high-rising. Tones in Chiang Mai dialect are very close to the standard Thai five tones systems and the equivalence can be drawn between the two. Lanna–Thai dictionaries often equate Chiang Mai tones with standard Thai tones, shown in a table below. Tone mark conjugation system of Tai Tham highly correlates with the system used by Thai script. Despite the difference in tone quality between Northern Thai, Tai Khuen, Thai, and Lao; equivalent words in each language are, in large part, marked with the same (or equivalent) tone mark. For example, the word ᨣ᩶ᩤ​ (; Khuen: ) which is equivalent to Thai ค้า (), and Lao ຄ້າ () all has the same meaning "to trade" and is expressed with the same or equivalent tone mark mai tho/mai kho jang but is pronounced with different tones differed by the languages. Tone mark conjugation in Tai Tham follows the same model used for Thai script. Consonants are divided into 3 classes: high, mid, low; with some degree of variation form Thai script due to the phonological differences between Northern Thai and standard Thai. Consonants in each class are combined with these tone marks to give a different tonal pattern. Only two tone marks mai yo (᩵)​ and mai kho jang (᩶)​ are mainly used. Low class and High class consonants only have one tone per one tone mark. Hence, to achieve the 6 tones while using only 2 tone marks (and one case of no tone mark), they are conjugated as a couple of the same sound. Notes Mid class consonants ([ʔ], [b], [d], and [j]) do not have a couple for tone conjugation. Hence, different tones can be expressed with the same tone mark. Readers have to rely on the context in order to know the correct tone pronunciation. Therefore, to solve this ambiguity, three new tone marks: mai ko nuea​ (᩷),​ mai song nuea​ (᩸), and mai sam nuea​ (᩹) were invented for the mid class consonants in Khuen language. However, these three new tone marks aren't used in Lanna spelling convention and even in Khuen, they are rarely used. The use of these new three tone marks is also not standardized and may also differ between the dialects of Khuen language. Moreover, similar to standard Thai, the tonal pattern for each consonant class