Learn Croatian: Pokazujete li im stručne sposobnosti? - Do you show them professional abilities?

In Croatian, small unstressed words called clitics must follow a strict order. The question particle li is the absolute boss of the clitic line—if it is in the sentence, it must be the very first clitic in the group! So here we have the first word (pokazujete), followed by li, and then the dative pronoun im (to them).

Could I ask this question using Da li instead?

Yes, absolutely! Da li im pokazujete stručne sposobnosti? is completely correct and actually more common in everyday spoken Croatian. Notice that if you use Da li, the pronoun clitic im jumps into the second position right after it. The Verb + li structure used in this example is slightly more formal, but very important to understand when reading or listening.

What case is im here?

It is the dative case of the pronoun "they" (oni), meaning "to them". In Croatian, the person you are showing something to is the indirect object, which always requires the dative case.

Why does the adjective stručne end in -e but the noun sposobnosti ends in -i? Aren't they both accusative plural?