Note: The è negative subject pronoun serves as the standard negation marker, but in accordance with vowel harmony, it changes to a negation of the ending letter of the pronoun (ex. in sentences with the pronoun mẹ, è shifts to ẹ̀). All negative subjection pronouns (with exception of ra) are in the low tone.Assimilation occurs between the negative pronouns, such that the negative marker assimilates the feature of the vowels of the pronouns.
Note: except for ín, object pronouns have a high tone following a low or mid tone monosyllabic verb, and a mid tone following a high tone. For complex verbs, the tone does not change.