Questions & Answers about Tiesikö tutkija, oliko uusi löytö vain vanha luu?
Why is oliko used here instead of a separate word for "if"?
In English, we use "if" or "whether" to introduce an indirect question (like "...if the discovery was..."). Finnish doesn't use a separate word for this; the word jos is strictly for conditional "if" (like "if it rains"). Instead, Finnish forms indirect questions by adding the question clitic -ko or -kö to the verb. So, oliko translates here to "if [it] was" or "whether [it] was".
Why does the sentence use the question clitic twice (tiesikö and oliko)?
Because the sentence essentially contains two yes/no questions joined together. The main clause is a direct question: Tiesikö tutkija...? (Did the researcher know...?). The second part is an indirect question: ...oliko uusi löytö... (...if the new discovery was...). Since Finnish uses the clitic for both direct and indirect yes/no questions, both verbs get one.
What is the infinitive of tiesikö, and why does it have an s?
The base verb is tietää (to know). When forming the past tense, many verbs ending in -tää or -taa change the t to an s before adding the past tense marker i. Therefore, tietää becomes tiesi (he/she/it knew), and adding the question clitic makes it tiesikö.
How are the nouns tutkija and related to verbs?