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

Because the correct use of “I’ll not” is “I wont”. That’s why it sounds unnatural, grammatically speaking.

ETA: I teach English in Europe and I tell my students that they can use those contractions while speaking, but not while writing, because it’s harder to convey tone that way. They should also never use it in a formal letter.