Learn Polish: Nie możemy pozwolić gościom przeszkadzać nowym klientom. - We cannot allow the guests to bother the new clients.

In Polish, certain verbs always require the dative case for the person being affected. Both pozwolić (to allow) and przeszkadzać (to bother or disturb) are verbs that take the dative. Since the guests are being allowed and the clients are being bothered, both take the dative form.

Is it a coincidence that both gościom and klientom end in -om?

Not at all! The dative plural is one of the most regular forms in Polish. Almost every single noun, no matter if it is masculine, feminine, or neuter, takes the -om ending in the dative plural.

How does the adjective ending work for nowym in the dative plural?

For adjectives in the dative plural, you use the ending -ym (or -im after soft consonants), regardless of the noun's gender. Here, the base adjective nowy drops the -y and adds -ym to match the dative plural noun klientom.

Why does this sentence have two infinitive verbs, pozwolić and przeszkadzać?

The first verb, możemy (we can), is a conjugated modal verb that requires the following action to be in the infinitive form, giving us pozwolić (to allow). In turn, allowing someone to do something requires another infinitive for that next action, which gives us przeszkadzać (to bother).