Student or Learner
Can I use the Present Simple tense in the following sentence?
Since my promotion, I'm a lot busier. I arrive earlier and leave later.
I'm not a teacher of English, but I have spoken it for (almost) all of my life....
(Not a Teacher)
You're sentences are okay, but I would use the present perfect continuous in the first sentence:
"Since my promotion, I've been a lot busier."