I am sorry. = Lo siento.

lo siento

there are several ways: lo siento, perdóname, discúlpame

dear rana , may I give you a small suggestion ,? a hint if you want ? spanish and italian seems sharing the same words , booth are latin languages , but the pronociation is totaly different and out of experience ,I know, you will mix them for example : the word difficult spanish = dificil italian= dif fi cile but here you must put the emphasis on the second part of the word (fi) while in spanish the word kept short, you see, have still fun with learning , bye