Hmm I never really thought about it. In terms of my worldview, I don't think people realize how hard English really is. When I was 13 or 14 I used to proof read my dad's reports at work for spelling and grammatical errors. And at 25 years old I still do that for him. He's been here almost 40 years and he still messes up when speaking and especially writing. I never had any issues understanding people with thicker accents no matter what country they were from. When I was traveling in Europe this Hungarian guy told me how much he appreciated how patient I was when he was trying to speak english to me. He said most people get very tired of trying understand him, but I'm very used to hearing bad english.

I'm trying to think of examples like yours. Feminine and Masculine conjugations were hard for me to grasp. I didn't understand the purpose of it because we don't have to worry about that in English. Arabic is written from right to left. So I notice arabic speakers will say some things backwards in english. Instead of 'burger king' my dad once said 'king burger'. There is no 'P' sound in the arabic alphabet so they pronounce with a 'B' sound. 'Pepsi' will come out like 'bebsi'. Not sure if that's what you're looking for.