awesome, challenging, daunting, enormous, formidable, great, Herculean, huge, mammoth, massive, monumental | arduous, demanding, difficult, exacting, exhausting, hard, laborious, onerous, stiff, time-consuming, tough, uphill | dangerous, hazardous
basic, easy, simple, small
Learning to drive requires patience, as passing the test is no simple task.
menial, mundane, repetitive, tedious | complex, mind-boggling | delicate, tricky | fruitless, hopeless, impossible | daily, day-to-day, routine
central, fundamental, important, main, major, primary, principal
The main task is to finish the report before Friday afternoon.
essential, vital | immediate, urgent | enviable, pleasant | thankless, unenviable, unpleasant | administrative, domestic, household, manual | self-appointed, self-imposed