SP Can speak -> present

present       integer       indicates if the speech functions of Speech Pack
                                    can succesfully be called.
                  At the moment these values can be returned:
                  -1    Speeck Pack is disabled by the SPEECH OFF command.
                   0     Speech Pack not usable, external package functions
                          can't be called.
                   1    Speech Pack usable, external package functions can be
                         called.
                   (2 and higher may be used later when other abilities are
                   added to the Speech Manager and these are implemented in
                   this external, so every value greater than zero implies
                   Speech Pack is available.)

Returns an integer indicating if you can use the Speech Pack functions to produce speech.

If SP Can Speak returns a value greater than zero,  all other functions can be used (except SP Count voices, SP VERSION and SP COPYRIGHT whom can always be called).
However, when the value returned is zero or negative and you call any of the other functions an error will be returned (-4).

When this function returns zero this means there are one or more conditions not met:
1) the Speech Manager is not installed (use SP VERSION to see if this
    is the case)
2) Speech Pack was unable to set up its private data when the data-base
    was launched, perhaps because not enough memory was available
    (only 984 bytes needed!).
3) when using a time-limited beta-version of Speech Pack the expiration
    date may have been passed and the external package refuses to
    function.
4) when using Speech Pack together with 4D Server the maximum
    number of users may be reached.

Example:
  $present := SP Can speak

  If ($present > 0)
    ALERT ("Speech Pack available.")
  Else
    ALERT ("Speech Pack not available.")
  End if