英语里动词在一个句子的开头是不是要变成ing形式？

Question

如题所述

Answer 1

你好。以下是动词开头的句子：
1
Come
again
tomorrow
if
you
can.(祈使句，省略了主语you)
2
To
learn
English
well
isn't
as
hard
as
you
think
.(带to的动词原形开头，作主语)
3
Learning
English
well
isn't
as
hard
as
you
think
.（动名词开头，作主语）