{$domain} outputs gramatically wrong text in langs other than english

What a long title

But it sums up the problem.

At checkout, if I apply a discount code, it will show:

English (All right!):
50% One Time Discount: R$ 149,50

Portuguese:
50% Uma vez Desconto: R$ 149,50
Should be 50% Desconto Uma vez: R$ 149,50

Spanish:
50% Una vez Descuento: R$ 149,50
50% Descuento Una vez : R$ 149,50

And so on with most non-english languages, Italian, French, German and others.

Perfect would be:
"50% discount on the first month: R$ 149,50
"Desconto de 50% no primeiro mês: R$ 149,50
"Descuento de 50% en el primer mes: R$ 149,50