Learn Finnish: Taivuttelen ystäväni, joka saa meidät osallistumaan kokeiluun. - I persuade my friend, who gets us to participate in the experiment.

This sentence demonstrates a specific grammatical structure: saada + object + 3rd infinitive illative (-maan/-mään). Together, this structure means 'to cause someone to do something' or 'to get someone to do something'. Here, saa meidät osallistumaan translates to 'gets us to participate'.

Why is the object meidät ending in -t instead of being in the partitive or genitive?

When personal pronouns are the total object of an action, they take a special accusative form ending in -t (like minut, sinut, meidät). Since the action of getting us to participate is viewed as a complete action here, the total object meidät is used.

Why is kokeiluun in the illative case (ending in -un) rather than the inessive (ending in -ssa)?

The verb osallistua (to participate) dictates the case of the word that follows it, which is called verb rection. In Finnish, you always participate 'into' something, so osallistua requires the illative case.

The word taivuttelen looks like it comes from the verb for bending. How does it mean 'persuade' here?

The root verb is taivuttaa, which literally means to bend something physical or to conjugate a word. The ending -ella makes it frequentative, implying a repeated or prolonged action. Figuratively, repeatedly bending someone's mind means to coax or taivutella (to persuade) them.