starting php by asking basic questions

i want to learn php and i do not know much and my english is also limited.isthere anyone who can explain me php by most simple example,like explainig to a child,something like this:if you put "this" symbol or writing, in your php script,when someone open this page,will see this message"long time not see" . at the moment ,i am scared of terms used by professionals. thnks,for many this could a stupid but this is what i am facing. thanks.