shall 
/ˈʃæl, ʃəl/ verb
past tense should /ˈʃæl, ʃəl/ verb /ˈʃʊd, ʃəd/; present tense for both singular and plural shall; negative shall not or shan't /ˈʃænt, Brit ˈʃɑ:nt/ [modal verb] formal 1 — used to say that something is expected to happen in the future ▪ We shall [=will] arrive tomorrow evening. ▪ I shall not mention it again. = I shan't mention it again. ▪ Perhaps it will happen. We shall see. 2 — used to ask for someone's opinion ▪ “Shall [=should] I call a taxi?” “Please do.” ▪ When shall we leave? [=when do you think we should leave?] ▪ Shall we dance? [=would you like to dance?] ▪ Let's dance, shall we? 3 — used to give a command or to say that you will or will not allow something to happen ▪ You shall leave at once! ▪ They shall not pass. 4 — used in laws or rules to say that something is required ▪ It shall be unlawful to carry firearms. ▪ The jury alone shall decide the verdict. ▪ There shall be no talking during the test. — see also shalt
