You can use the + operator to concatenate strings, single characters, numbers, floats and boolean values.
var
sString : string;
sString1, sString2 : string;
i : number init 42;
f : float init 23.5;
b : boolean init true;
begin
sString1 := "The ";
sString2 := "sun ";
sString := sString1 + sString2 + "is " + "r" + 'I' +
's' + "ing" + '.';
write(sString); writeln;
writeln("number: " + i);
println("float: " + f);
println("boolean: " + b);
end;
The sun is rising. number: 42 float: 23.50000 boolean: TRUE