Learn Turkish: Oyuncak kutunun içinde.

In Turkish, spatial locations like 'inside', 'on', or 'under' act like nouns being owned by another object. So instead of saying 'inside the box,' you literally say 'at the box's inside.' That is why kutu (box) takes the genitive (possessive) suffix -nun, becoming kutunun.

What do all the suffixes on 'içinde' mean?

The base word is iç (inside or interior). We add -i to mean 'its' (matching the box). Then we need the locative suffix -de to mean 'in' or 'at'. Because we are adding a location suffix to a third-person possessive suffix (-i), Turkish requires the buffer letter -n- between them. So it is: iç + -i + -n- + -de.

Why is there an extra 'n' in 'kutunun'?

The word kutu ends in a vowel. The genitive suffix (which means 'of' or shows ownership) here is -un. To stop the two vowels from crashing together, Turkish uses the buffer letter -n-. That gives us kutu + -n- + -un.

Can I just say 'Oyuncak kutuda' instead?

Yes! Oyuncak kutuda simply means 'The toy is in the box' using the basic locative case (-da). Saying Oyuncak kutunun içinde is just more specific, emphasizing that the toy is physically inside the enclosed space of the box.