Other vs. another (muu, toinen)

Using Toinen (Another / The Other)

English uses "other" and "another" in many ways, but Finnish splits these concepts into two distinct words.

The pronoun toinen is used when referring to "another" (an additional one of the same kind) or "the other" (a specific alternative, or the second of two).

Like most Finnish pronouns, toinen changes to match the case of the noun it describes. Before endings are added, its stem becomes toise- (for example, the inessive case is toisessa and the adessive is toisella). The partitive form is toista.

A very common and useful Finnish structure is toinen... ja toinen, which translates to "one... and the other".

Using Muu (Other / Else)

The pronoun muu is used when referring to a distinctly different kind of thing, "the rest" of a group, or when expressing "else".

Its stem is simply muu-, making its partitive form muuta and its inessive form muussa.

You will frequently see muu paired with indefinite pronouns like jokin (some) or mikään (any). In these pairings, both words inflect in the same case. For example, jokin muu means "something else", and mitään muuta means "anything else".

Case Agreement and Plurals

Remember that whenever toinen or muu acts as an adjective describing a noun, it must agree with that noun in both case and number.

When dealing with plural nouns, the stem for muu becomes mui-. For instance, adding the plural genitive ending gives you muiden (of the other / of the others).