"Nunca he visto un volcán."
Translation:I have never seen a volcano.
In case you swype, you can adjust the settings to swype in Spanish, too. There's even a shortcut to switch languages/keyboard. Just swype from the swype key to the space bar. The Spanish keyboard gives you the ñ and the upside down punctuation ¿ ¡ Of course that might not help you learn the accents as well as typing them individually.
Simply put, it's a different tense than the one presented. "Nunca he visto" is the present perfect, which, in English, is, "I have never seen." "I had never seen" is past perfect, and would be written, "nunca había visto" in Spanish. The above comment explains the practical differences between the two tenses very well.