be to和be going to
be to 表示客观安排或受人指示而做某事。
be going to 表示主观的打算或计划。
I am to play football tomorrow afternoon. (客观安排)
I'm going to play football tomorrow afternoon. (主观安排)
英语四级语法：be to和be going to
大学英语四级语法大全目录
be to 表示客观安排或受人指示而做某事。
be going to 表示主观的打算或计划。
I am to play football tomorrow afternoon. (客观安排)
I'm going to play football tomorrow afternoon. (主观安排)
From:https://www.zgghmh.com/CET-4/20001538.asp