Main.c: In function 'main': Main.c:10:2: warning: implicit declaration of function 'elif' [-Wimplicit-function-declaration] elif (a>=97 && a<=122){ ^ Main.c:10:24: error: expected ';' before '{' token elif (a>=97 && a<=122){ ^ Main.c:5:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&a); ^