Learn Finnish: Minun täytyy siirtää tuo kuppi roskakoriin. - I must move that cup into the trash can.

This is the illative case, which means 'into' and answers the question mihin (into where?). To make it, take the base word roskakori (trash can), double the final vowel (i), and add -n. This gives us roskakoriin.

Why does the sentence start with minun instead of minä?

The verb täytyy (must) has a special rule: the person who must do something has to be in the genitive case. So, minä (I) changes to minun.

Why doesn't the verb täytyy change to match 'I'?

Täytyy is a unique verb that never changes its shape based on who is doing the action. Whether it is minun täytyy (I must) or hänen täytyy (he/she must), the verb stays exactly the same.

Why is the verb siirtää in its basic dictionary form?

When you use a necessity verb like täytyy, the action verb that follows it always stays in its basic form (the infinitive). You do not conjugate it.

Could I use se instead of tuo to say 'that' cup?