Aalto published on the Latin gerundive, the Latin gerund, the Greek infinitive, the history of the Finnish study of Oriental, classical, and modern languages.
He edited Ramstedt's comparative Altaic grammar and completed an edition of the Mongolian version of the Pan̂carakṣā and a collection of Latin sources of Northeast Asian peoples.
He is also the first to translate the ancient Tamil moral text of the Tirukkural into Finnish.
[2] Aalto has mentored several Finnish Indologists, including Asko Parpola.
In 1969, his team led by his pupil and successor Parpola, announced its interpretation of the script of the ancient Indus civilization.