1. How does expect knows when is typing of input possible (when I can invoke send) ?

eg. Is expect capable to process also text that appears on screen but (user) input is not expected (in normal circumstances) ?
- or in other words, how expect know if app has input available or requires user interaction or what is the correct name

2. Does TCL=Expect ?
- or expect uses TCL ?

3. Does expect supports some kind of looping
- eg. If same text appears on screen which will match "expect" pattern (requesting password) the different "send" action will be called (passing next element from array)?
- in other words: How to "expect" same pattern for several times but "send" another string

4. Does expect supports something opposite to regexp, or negation of regexp ?
- eg. expecting some string in loop and calling send (passing password) but do another action if expect wont match string (password was guessed or chances expired)
- in other words: How to "expect" same pattern for several times and "send" another string but after not matching "expect"

            spawn ssh ${SSHOpts} ${UserName}@${server}
            expect {
                "timed out" {
                    logWrite ${oFile} ${server} "ERROR: Timed out"
                    continue
                }
                "reset by peer" {
                    logWrite ${oFile} ${server} "ERROR: Connection reset"
                    continue
                }
                "failure in name resolution" {
                    logWrite ${oFile} ${server} "ERROR: Host not found"
                    wait
                    continue
                }
                "(yes/no)?" {
                    send "yes\r"
                    exp_continue
                }
                "*word:" {
              ..........

5. In my situation, when I just want to know right password (connecting to server and after exiting) is command "interact" (or statement or whatever it is called) required ?

6. What exactly does exp_continue doing ? It seems like if it wont wait for requested input until "send" is invoked, is there some timeout or something similar ?
- eg. is possible to invoke "exp_continue" to repeat "send" but with different arguments and when "expect" wont match the exp_continue will break ?

7. Is possible to do some basic if else construction in input matching (in "expect")
- I would also handle following message "continue connecting yes/no"