Eli5 – How would you explain when to use “I’ll” vs “I will” to someone who isn’t a native speaker?

Question

For example why does it sound unnatural to say “I’ll not use this for profit.”?

In: 0

Answer 1

That phrase sounds unnatural because it’s common to contract “I will not” to “I won’t” instead of “I’ll not”.

You also want to avoid having “I’ll” be a phrase all on its own. Something like “If she doesn’t, I’ll” sounds awkward. You have to have more to say about what it is you will be doing.