Both "gimnasio" and "gymnasium" are correct, but they are used in different languages. "Gimnasio" is the correct term in Spanish, and it means "gymnasium" or "gym" in English. So, if you are speaking or writing in Spanish, you would use "gimnasio."

The word "uniquer" is technically not incorrect, but it is not commonly used in standard English. The word "unique" is already a superlative, meaning it describes something that is one of a kind or singular, having no equal or equivalent.

"Liason" is an incorrect spelling. The correct spelling is "liaison." "Liaison" is a noun that refers to a connection, communication, or coordination between two or more parties or groups.

"Dieing" refers to the process of creating precise shapes or forms in metal or other materials using dies. "Dying" is a verb that describes the act of ceasing to live or exist.

"Occured" is an incorrect spelling of the word. The correct spelling is "occurred" with double "r." "Occurred" is a verb in the English language that means something has happened or taken place. It is often used to describe an event, incident, or situation that has happened in the past.

"Backround" is not the correct spelling. The correct spelling is "background" with the letter "g." "Background" refers to the circumstances, events, or conditions that precede or surround a particular situation or person.