The Mariners have never won the World Series.
The Mariners have never won a world series. (so far)
No, the Seattle Mariners have never won the World Series.
No. The Mariners have never won the AL and advanced to the World Series.
No they have not.
The Seattle Mariners is one of two major league baseball franchises that have never appeared in a World Series. The Washington Nationals in the other.
The Mariners have never won the world series.
They have never won a World Series title.
The mariners are one of three current baseball franchises to have never made the world series. The other two are the Washington Nationals and (at the time of this writing) the Texas Rangers
Eight teams haven't won the World Series: the Padres, Rangers, Rays, Rockies, Astros, Brewers, Mariners and Nationals (formely the Expos). The Nationals and the Mariners have yet to even make it to the World Series.
As of the start of the 2008 season, the Mariners have never played in a World Series.
Through the 2008 season, the Texas Rangers, Tampa Bay Rays, and Seattle Mariners have not won a World Series.