Breakdown of Hän on kumppani, jonka verkosto on luotettava.
olla
to be
hän
he / she
joka
who / which (relative pronoun)
luotettava
reliable
Questions & Answers about Hän on kumppani, jonka verkosto on luotettava.
Why do we use jonka here instead of joka?
jonka is the genitive (possessive) form of the relative pronoun joka. Just like "who" becomes "whose" in English to show possession, joka becomes jonka to show that the network belongs to the partner.
Would jonka change if we were talking about multiple networks?
No! The relative pronoun joka gets its number (singular or plural) from the word it refers back to, not the word it owns. Because it refers back to a single partner (kumppani), it stays in the singular genitive jonka, even if the partner had many networks (jonka verkostot).
How would this sentence change if we were talking about multiple partners?
If the main clause was "They are partners" (He ovat kumppaneita), the relative pronoun would need to be in the plural genitive form because it refers back to a plural word. "Whose" would change from jonka to joiden: He ovat kumppaneita, joiden verkosto on luotettava.
What is the word luotettava based on?
luotettava (reliable/trustworthy) comes from the verb luottaa (to trust). The -ttava/-ttävä ending works a bit like "-able" in English, turning a verb into an adjective that describes something that can be trusted.