Completar frases Modals: ability or obligation2Versión en línea practice these modal verbs por Alvar Garcia Soriano 1 doesn't to have to don't to mustn't don't mustn't mustn't have to have don't have mustn't Put in ? mustn't' or ? don't / doesn't have to' : We have a lot of work tomorrow . You be late . You tell anyone what I just told you . It's a secret . The museum is free . You pay to get in . Children tell lies . It's very disgusting John's a millionaire . He go to work . I do my washing , because my mother does it for me . We run . We've a lot of time . You smoke inside the school .