Hello, Suvajit. Two phrases need some changes, as follows: "¿Puede repetir por favor?" needs a comma after "repetir." It will be as follows: "¿Puede repetir, por favor?" Also, "Como esta Usted?" should be "¿Cómo está usted?" The phrase you submitted needs to include three important things: 1) "¿Cómo" 2) "está 3) "usted?" For 1) It's important to use the accent over the "o" in "cómo" because you are asking "how." Not including the accent mark changes the meaning of the word....."como" becomes the word "like" and "around," instead of "How?" 2) "esta" needs an accent mark, because if it's omitted, the word "esta" means "this," instead of "are" as in "está." Lastly, 3) The use of a capital "U" in "usted" is not necessary. The phrase properly reads: "¿Cómo está usted?" As far as the rules for symbols, I can share two: When asking a question in writing, an inverted question mark, "¿" must be used before certain words to avoid confusion, as these certain words can mean different things when stated versus when asked. For example, the words "es" "quien" and "que" serve one purpose when proceeded by the "¿" and they serve another when they stand by themselves. A little confusing, but if you look out for this when you're reading Spanish, you'll start to notice the differences in meaning for these kinds of words. Also, an inverted exclamation mark "¡" is used to indicate a strong opinion or feeling - for example: "Cierra la puerta, ¡hace frío!" lets you know it's REALLY cold! Take care. Monique Rosales.