Breakdown of Vaikka hän juonittelee, hän ei suostu petokseen.
hän
he / she
ei
no / not (negative verb)
suostua
to agree, to consent
vaikka
although / even though
Questions & Answers about Vaikka hän juonittelee, hän ei suostu petokseen.
Why is petokseen in the illative case here?
The verb suostua (to consent, to agree to) requires its target to be in the illative case. While in English you agree 'to' something, Finnish grammar visualizes consenting as stepping 'into' the agreement, which is why it takes the illative (into) case.
What is the base form of petokseen, and how does its stem change?
The base word is petos (betrayal, fraud, or deceit). For nouns ending in -os or -ös, the final -s changes to -kse- before adding case endings. The illative ending here is -en, creating petokseen.
How is the verb juonittelee related to the noun juoni (a plot)?
The verb juonitella (to scheme or plot) is derived directly from the noun juoni (plot, scheme, or storyline). The suffix -tella is added to create a verb that implies continuous, repeated, or casual action.
Could I use the verb sopia instead of suostua to mean 'agree'?
Not in this context. Sopia means to reach a mutual agreement or to agree with someone. Suostua means to consent, yield, or give in to something that has been proposed or demanded. Since he is refusing to participate in a proposed betrayal, suostua is the right choice.