lisäisi

Lisäisi is a Finnish verb form meaning would add, used as the third-person singular conditional mood of the verb lisätä, which means to add. It expresses a hypothetical or potential action in the present or future and is often found in clauses joined by if (jos) or in polite or tentative statements.

In usage, lisäisi appears in subordinate conditional clauses and can be translated as would add in English. For example, in a sentence like Jos hän lisäisi vähän suolaa, ruoka maistuisi paremmin, the clause lisäisi expresses the hypothetical action of adding salt. The form is part of a larger conditional system in Finnish, where the other persons and numbers use corresponding forms such as lisäisin, lisäisit, lisäisimme, lisäisitte, and lisäisivät.

Grammatically, lisäisi is derived from the stem lisätä with the conditional suffix -isi and the appropriate personal ending. It is used with third-person singular subjects and can appear in both written and spoken Finnish. While it specifically denotes a hypothetical addition, its meaning can extend to broader tentative or polite suggestions about quantities, materials, or actions.

Related forms include lisäisin (I would add), lisäisit (you would add), lisäisimme (we would add), lisäisitte (you would add), and lisäisivät (they would add). The root lisätä belongs to the core verb family meaning to add or supplement, and lisäisi is one common realization in conditional constructions. See also lisätä for the base verb and its other conjugations.