Cool! Okay, here's what I'm doing. English is my language, but I'm fairly fluent in German. Modal verbs are strange there too. (Unpredictable.) I love "Le Petit Prince". Because I’ve been getting help from France, a very nice guy has been helping me with reading his language. And modal verbs in French are hard too. To help with my own study, I found that comparing translations of Spanish along with German and English is helping me understand French. Starting with NO knowledge of Spanish, I’ve been picking up Spanish (a bit), subconsciously, and so I’ve run across these same "modal probems" in Spanish. In short, these verbs are HARD in EVERY language.
There are no final answers. Just in case, here a few ideas, off the top of my head.
Americans say: "Can I help you?" Strict grammarians will tell you this is wrong. They will tell you that you must use "May I help you?" Using "can" is informal and used a great deal in the US.
"Might I help you" is very polite in the US, almost antiquated, but I believe it is used more in the UK. Perhaps someone from there will give an opinion.
However, in meaning, these are the same thing:
Can I help you?=May I help you?=Might I help you?
And that’s the problem. In another situation, these words (modals) may not mean the same thing at all. One minute you can move back and forth between words in these different languages, and it works. The next, it doesn’t at all. Because context is SO important. An example:
"You may go" may used as a polite command (permission to leave, from a king, for instance), OR it may be a parent giving permission to DO something: "Mom can/may I go to the mall?"
"Yes, you can/may go."
There must be thousands of such examples, all depending on context. If any one wishes, I’ll show other places where words such as "may", "might", "can", etc. may either mean the same thing OR something very different.
If this is totally confusing, "may I"/"could I"/"micht I" have a second change to explain?