Japanese people very often use particle で when ordering something. For example, when they order a cup of coffee, they would use で to tell the size: ラージサイズで！ What is this で? Textbooks typically don't mention this particular use of particle で, so many Japanese learners don't know this function of particle で, but it's very useful in everyday Japanese. If you don't know about it, better learn it now. Support the channel: https://www.patreon.com/KanameNaito