The Indefinite Suffix: -то
In Russian, you can add the suffix -то to question words to talk about unknown but specific people, things, places, or reasons. You use -то when you know that an event happened or someone exists, but you don't know exactly who or what it was.
Кто-то and Что-то
Adding -то to кто (who) creates кто-то (someone). Adding it to что (what) creates что-то (something). These behave exactly like the base question words and change cases depending on their role in the sentence.
Почему-то: For some reason
You can also attach -то to question adverbs. For example, почему (why) becomes почему-то (for some reason).
Какой-то: Some kind of
To say "some" or "some kind of" before a noun, use какой-то. Because it is based on the adjective какой, it changes its gender, number, and case to match the noun it describes.
Где-то and Куда-то: Somewhere
Just as где and куда distinguish between location and destination, so do their indefinite forms:
- где-то means "somewhere" (where an action happens or a thing is located).
- куда-то means "somewhere" (the destination of a movement).
Когда-то: Once
Finally, adding -то to когда (when) gives you когда-то. This translates to "once," "formerly," or "at some time" in the past.
