Dear Fellow Engineer,
Can you be more specific in the sense:
1. Why do you need ISA 5.1, and what is your application
2. ISA has throughly revised the Standard. Now it is very descriptive and quite self-explanatory, still what problems have you faced in understanding it.
3. Are your problems related to the graphic part or the textual part?
4. To begin ask a few questions about one or two symbols.
5. What sort of examples do you feel can help you?

The more you are specific, the more forum members will be able to assist you.

Do not worry about your English, as long as you are able to put your message through.

Regards,
Sajid Ali Khan