The 29-year-old moved to the Spanish capital from Tottenham Hotspur in the summer of 2013 but is yet to pick up the language.
Toshack, who spent much of his management career overseas including spells in Spain with Real Sociedad, Real Madrid, Deportivo and Real Murcia, underlined the importance of making the effort to learn Spanish.
“If you move to a team abroad, you should learn the language out of respect for the fans,” Toshack told Onda Cero.
“Bale needs to make an effort and if he does that will help him. He is a truly great player but has been restricted been injuries.”
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