Learn Swedish: De struntar i regnet eftersom de längtar efter stranden. - They ignore the rain because they long for the beach.

The phrase strunta i is a fixed verb and preposition combination that means to ignore or to not care about something. In Swedish, you cannot just use this verb on its own to mean ignore — it must be followed by i.

Can I use för instead of efter since the English translation is 'long for'?

No, you have to use efter. Swedish verb-preposition pairs often do not translate directly from English. The verb längta (to long or yearn) almost always pairs with efter when you are talking about longing for or missing a place, thing, or person.

Could I use the Swedish word ignorera instead of strunta i?

You could, but strunta i is much more natural and common in everyday speech. It gives the feeling of simply not bothering to care about the rain. ignorera sounds more formal, or like you are actively giving someone or something the silent treatment.

Does the word eftersom change the word order here?

eftersom (because) starts a subordinate clause (a dependent part of the sentence), so the subject and verb stay in their normal order: de längtar. However, this is a great time to remember your word order rules: if you added a word like inte (not) here, it would have to jump before the verb: eftersom de inte längtar efter stranden.