Farsi and Arabic are not even remotely related, so I don’t think that is the right thing to say as an example. Also, Farsi, like English, is Indo-European. Arabic is Semitic. So if anything, Farsi and English are much closer to each other than Arabic and either of them.
Languages from groups right next to each other do not have to be related at all. Finnish and Swedish were mentioned above. Swedish is Indo-European, Finnish is Uralic.
Farsi and Arabic are not even remotely related, so I don’t think that is the right thing to say as an example. Also, Farsi, like English, is Indo-European. Arabic is Semitic. So if anything, Farsi and English are much closer to each other than Arabic and either of them.
Languages from groups right next to each other do not have to be related at all. Finnish and Swedish were mentioned above. Swedish is Indo-European, Finnish is Uralic.