Yet more prepositions which are shared with other cases.  The top few are all shared with Instrumental (Narzędnik), but the difference is that you use Accusative when there’s motion involved.  Similarly some of the latter ones are shared with the Locative (Miejszownik) case.

Kot wszedł pod łóżko <ACC>

The cat went under the bed (motion is involved, so bed is in Accusative)

Kot śpi pod łóżkiem <INS>

The cat is sleeping under the bed (location is involved, not movement so bed is in Instrumental)

Don’t worry too much about the details for now, more explanation and examples to follow.  For now, just treat these as a group of prepositions to learn which will help you be more descriptive in your sentences.