For example, the plural form of "po" "s/he" is "ayfo" "they", with the "p" weakening into an "f" after the prefix "ay-." Lenition has its own significance when the plural prefix can optionally be omitted. In the above example, "ayfo" can be shortened to "fo". Similarly, the plural of "tsmukan" "brother" can be "smukan" (from "aysmukan"). Naʼvi has free word order. For example, the English "I see you" (a common greeting in Naʼvi), can be as follows in Naʼvi:  "Oel ngati kameie"  "Ngati oel kameie"  "Oel kameie ngati"  All forms of "I see you" in Naʼvi are completely correct. As sentences become more complex though, some words, like adjectives and negatives, will have to stay in a more or less fixed position in the sentence, depending on what the adjective or negative is describing. "Today is a good day"  "Fìtrr lu sìltsana trr"  "Sìltsana trr fìtrr lu"  In this case, the adjective "sìltsan(a)" (good) will need to stay with the noun "trr" (day), therefore limiting the sentence to fewer combinations on the construction of the sentence, but as long as it follows or precedes the noun, the sentence is fine. By putting the attributive "a" before the adjective, the adjective can be put after the noun:  "Fìtrr lu trr asìltsan"  More information about this can be found in the "Adjectives" section. Nouns in Naʼvi show greater number distinctions than those in most human languages do: besides singular and plural, they not only have special dual forms for two of an item (eyes, hands, lovers, etc.), which are common in human language (English has a remnant in "both"), but also trial forms for three of an item, which on Earth are only found with pronouns. Gender is only occasionally (and optionally) marked. The plural prefix is "ay+," and the dual is "me+." Both trigger lenition (indicated by the "+" signs rather than the hyphens that usually mark prefix boundaries).