Error de compilación ISO C++ forbids comparison between pointer

HELP
7 LEDS TURN FOR LOVE AND MADE THE APPS BLUETHOT
LETTERS SENT BY YOU TO ARDUINO BLUETHOOTH

AND DID THE CODE ERROR ARDUINO BRAND ME BUT when compiling. THIS IS THE CODE

void setup()
{
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);

Serial.begin(9600);
}

void loop()
{
char dato = Serial.read();
if (dato =="a")digitalWrite(2,HIGH);
if (dato =="b")digitalWrite(2,LOW);
if (dato =="c")digitalWrite(3,HIGH);
if (dato =="d")digitalWrite(3,LOW);
if (dato =="e")digitalWrite(4,HIGH);
if (dato =="f")digitalWrite(4,LOW);
if (dato =="g")digitalWrite(5,HIGH]);
if (dato =="h")digitalWrite(5,LOW);
if (dato =="i")digitalWrite(12,HIGH);
if (dato =="j")digitalWrite(12,LOW);
if (dato =="k")digitalWrite(13,HIGH);
if (dato =="l")digitalWrite(13,LOW);
}

   if (dato =='a')
digitalWrite(5,HIGH]);

There's your next problem.

Please don't SHOUT

Use 'a' instead of "a".

You only want to compare a single character, not a whole string (and you were actually comparing the pointer to the string).