The Japanese are a spiritual people who anthropomorphize inaminate things. They will thank the warmth of sunlight, turn a tea bowl so that the "good" side faces the other person, and they are very attuned to physical and atmospheric elements. So when Marie suggests thanking a piece of clothing that one is discarding, it makes perfect sense.
She is adorable. And as for the language barrier-- English is one of the most difficult languages for an adult to learn. Kids who are taught English in school are really lucky. But English, unlike most other languages, doesn't follow standard and consistent rules. It's very difficult to learn compared to other languages. Japanese might be one of the easiest languages to learn. So don't get down on Kondo for not being fluent in our language.
