Its is just a matter of if...else...
#include <stdio.h>
#include <string.h>
int main(void){
int n=0;
char str[20];
while(fgets(str,20,stdin)){
size_t ln = strlen(str) - 1;
if (*str && str[ln] == '\n')
str[ln] = '\0';
if(str[0]=='#') { break; }
if(strcmp(str,"HELLO")==0){
printf("Case %d: ",++n);
puts("ENGLISH\n");
}
else if(strcmp(str,"HOLA")==0){
printf("Case %d: ",++n);
puts("SPANISH\n");
}
else if(strcmp(str,"HALLO")==0){
printf("Case %d: ",++n);
puts("GERMAN\n");
}
else if(strcmp(str,"BONJOUR")==0){
printf("Case %d: ",++n);
puts("FRENCH\n");
}
else if(strcmp(str,"CIAO")==0){
printf("Case %d: ",++n);
puts("ITALIAN\n");
}
else if(strcmp(str,"ZDRAVSTVUJTE")==0){
printf("Case %d: ",++n);
puts("RUSSIAN\n");
}
else{
printf("Case %d: ",++n);
puts("UNKNOWN\n");
}
}
return 0;
}