No, you can only keep him on the levels that has him. If you finish the level on/with Yoshi, he'll wave bye while you go in the castle, but if you know a certain glitch you can start out every lvl with yoshi.
Did you mean New Super Mario Bros.? Yoshi isn't in that, but he is playable in Super Mario 64 DS, and you can ride him in New Super Mario Bros. Wii!
Yoshi was in Super Mario World but has never been in a Mario Bros. Game. that is, until New Super Mario Bros Wii comes out.
you can not.Only in new super Mario bros wii you can ride Yoshi but you can't play as him
Many people think that you can be Yoshi in New Super Mario Bros. DS, but you cant.
you can not play as Yoshi in new super Mario bros DS
Unfortunately no
he isn't in super Mario bros 3
There is only a Yoshi in the wii version, in which he is not a playable character.
Just finish classic mode with Mario and Yoshi.
There are several games of 2012 which feature Super Mario. Some examples of these games are Super Mario Bros: The Lost Levels, Super Mario Bros U, and Yoshi.
13 Yoshi games 2 unreleashed games [Super Mario Galaxy 2 and new Super Mario bros for the Wii]
There is no way to play as Yoshi in New Super Mario Bros. You can play as Luigi, and you can ride a Yoshi in New Super Mario Bros. Wii, but Yoshi does not even appear in the New Super Mario Bros. story.