The words we use are important, much less because of the words themselves than because of the meaning we give these words. Meaning depends on the meaning intended as well as the context in which they are placed.
In general, there is only one way to learn to know the meaning as it meant, and that is to ask the person. The second best thing is to pay attention to how it is being said.
But then there are also these details we rarely make ourselves really aware of. Sometimes we are so used to some expressions that we don’t think about their meaning.
“Do. Or do not. There is no try.” – Yoda
“I’ll try” is such an expression. While there might be a few situations in which trying might be the adequate wording, it rarely is for actions we undertake. We cannot try to stand up, either we stand up or not.
The reason people use “I’ll try” is that it gives them a mattress on which to fall if they fail. At the same time, it is the reason why they often fail.
The problem isn’t failing, it’s the story we tell ourselves about failing.