Anne Vainikka (July 31, 1958 - June 11, 2018) was a Finnish linguist specialising in the syntax of second language acquisition (SLA). She was most notable within linguistics and SLA for developing the Minimal Trees Hypothesis with Martha Young-Scholten, an "important theory," where 'tree' is a metaphor of syntax for the branching structure showing how words of a phrase or sentence co-relate. The hypothesis concerns what aspects of a language learner's first language (L1) is carried over into the grammar of their second language (L2), in addition to mechanisms of universal grammar that allow new acquisition to take place.