Home situation

If you live in the Netherlands and want to keep living there, it seems to me that they only need to learn one language: Dutch. What could come in handy, though, is being proficient in English alongside Dutch. I never really understand why people living in the Netherlands feel the need to speak another language?

I learned during my training to advise parents to teach their child their home language. Which language do you and your husband speak to each other? That’s the language your daughter will hear most often at home. So I’d choose that language. A child needs to develop their home language first before they’re open to other languages. Of course, you can practice some words, etc. But I’d really recommend speaking in the language you use at home. What do you speak to each other?

My husband and I are having a daughter. I'm Dutch and my husband is Iranian. We speak Dutch to each other, and we'd like her to learn the basics in Persian when she's a bit older. My entire in-law family still lives there and speaks little to no English. I think it would be nice for them if they could talk to their granddaughter/niece, even if it's just a few sentences, and my husband can translate the rest.
But learning three languages seems a bit difficult...

We're both Moroccan, but we only speak Dutch with him.
He does learn Moroccan from grandma and grandpa hahaha.