Learn Dutch: Ik vraag hulp aan mijn collega. - I ask my colleague for help.

When you drop aan, you must rely on strict word order. The indirect object (mijn collega) must be placed right before the direct object (hulp). The sentence becomes: Ik vraag mijn collega hulp.

Why is aan used here instead of voor?

We use aan when an action is directed to someone (like asking, giving, or telling). We use voor when we do something for the benefit of someone (like buying or making something). Since you are directing a request to your colleague, aan is the correct choice.

The English translation says "ask for help", but there is no word for "for" in the Dutch sentence. Why?

In Dutch, you can just use vragen followed by a direct object (hulp) to mean "ask for". You are literally saying "I ask help to my colleague." However, Dutch also uses the phrase vragen om (to ask for), so another very natural way to translate this is: Ik vraag mijn collega om hulp.

Can I put the direct object at the end and say: Ik vraag aan mijn collega hulp?