我保证我绝对不会再让你落单翻译

Answer 1

I promise you not to let you fall behind / stay alone / stay lonely any more.
I promise (you) that I will never let you fall behind / stay alone / stay lonely any more.

Answer 2

I swear that i will never let you fall behind.

Answer 3

I promise you i won't let you alone any more

Answer 4

I promise that i will never let you alone