lisääntyisivät

"Lisääntyisivät" is the conditional form of the Finnish verb "lisääntyä," which translates to "to increase," "to multiply," "to reproduce," or "to proliferate." The conditional mood in Finnish expresses a hypothetical or potential situation. Therefore, "lisääntyisivät" conveys the idea of "they would increase," "they would multiply," "they would reproduce," or "they would proliferate."

This form is used when discussing scenarios that are not certain but are considered possible or desirable under certain circumstances. For example, one might say "Jos sää olisi parempi, turisteja lisääntyisivät" which translates to "If the weather were better, the tourists would increase." Another example could be in a biological context, such as "Pestit lisääntyisivät nopeasti, jos niitä ei torjuttaisi" meaning "The pests would multiply rapidly if they were not controlled."

The suffix "-isivät" is the third-person plural conditional ending for verbs in Finnish. It indicates that the subject of the verb is plural and refers to "they." The base verb "lisääntyä" itself is a reflexive verb, often implying an increase or multiplication occurring naturally or by itself. Thus, "lisääntyisivät" specifically refers to a potential, hypothetical increase or multiplication by a plural subject.