äitiinsä

äitiinsä is a Finnish noun phrase formed from äiti (mother) plus the third-person possessive suffix -nsä, traditionally yielding the meaning “his/her mother.” In standard Finnish, the correct written form is vaak in practice äitinsä, with the possessive suffix attaching directly to the stem and producing a single i before the suffix. The form äitiinsä, with two consecutive i’s, is not considered standard and is generally viewed as a nonstandard spelling or typographical error. Some older texts or dialectal writings may show such variants, but äitinsä is the form used in contemporary standard Finnish.

Usage of äitinsä follows the general possessive construction in Finnish. It denotes that the mother belongs to or is possessed by a third person. It can appear in various syntactic positions just like other nouns in Finnish, and it inflects for the surrounding grammar in noun phrases. For example, in a sentence like Hän puhui äitinsä kanssa, the phrase means “He spoke with his mother.” The possessive suffix -nsä marks the possessor without requiring an additional possessive pronoun in many contexts.

Etymology and structure: äiti is the root meaning mother, and -nsä is the 3rd person singular possessive suffix attached to the noun, a common pattern for forming “his/her [X]” in Finnish. Spelling conventions align with standard orthography, which typically uses äitinsä rather than äitiinsä.

See also: Finnish possessive suffixes, Finnish grammar, äiti.