如果你想表达你怀念你的爷爷，你可以用英语说 "I miss my grandfather"。这句话的来源是从动词 "miss" 和名词 "grandfather" 构成，"miss" 的意思是思念、想念，"grandfather" 是祖父的意思。例句如下：
I miss my grandfather very much. 我非常怀念我的爷爷。
I haven't seen my grandfather in a long time. 我很久没有见到我的爷爷了。
My grandfather was always there for me when I needed him. 我需要的时候，我的爷爷总是在那里。
希望这些信息能够帮助你。