What is the ruling on a husband leading his wife in prayer when he sometimes makes mistakes in recitation and does not know the rules of Tajwid?

The error that invalidates the prayer is what occurs in Al-Fatihah and changes the meaning, such as pronouncing the letter 'taa' with a 'dammah' in "an'amta" (rendering it "an'amtu"). Other than that, it must be avoided, but if it occurs unintentionally, it does not invalidate the prayer for the worshipper nor for those praying behind him. If the husband's error does not invalidate his prayer, then his leading his wife and others in prayer is permissible.