explaining Bare Infinitive

[paikiah]

What would be the shorest and easiest way to tell a student about bare infinitives?

I didn't know it would be this hard to explain something that I always thought was second nature, or had to be learnt by reading many books.

I have long, long explanations and examples, but I need to find a way to make it shorter somehow..:(

I've hit a wall, and I can't seem to climb over it for 4~5 hours now.

[paikiah]

Could it be due to the fact that the meaning of "to" means it has a set goal or leads to something?

(just like "in" has a limitation whilst "at" has none?)

[Tdol]

A bare infinitve doesn't have 'to'.