Yes, I need to explain this. Explain is a tough word for Spanish speakers. It trips up even the most advanced of speakers.
I see this type of sentence a lot:
Incorrect: They can explain us what sources to use.
Correct: They can explain what sources to use.
Incorrect: Can you explain me this?
Correct: Can you explain this (to me)?
Fortunately, the mistake is very easy to fix!
The structure is ALWAYS:
explain + direct object (explain what?)
And the indirect object is often optional:
explain + direct object (explain what?) + indirect object (to whom?)
There are more verbs like this as well. I found some more examples here:
Existe un grupo de verbos ditransitivos que solamente permiten la configuración Complemento directo seguido por el complemento indirecto: donate, push, carry, explain, suggest, describe, take.
donate money to the museum (y no: donate the museum money)
carry the baby to the doctor (y no: carry the doctor the baby)
suggest a good restaurant to me (y no: suggest me a good restaurant)
explain your decision to the director (y no: explain the director your decision)
describe your friend to us (y no: describe us your friend)
