ADJ
- big, considerable, enormous, great, huge, radical, real, serious, significant, strong
- difficult, tough
- major, main
- fresh, new
- exciting, interesting
- economic, environmental, intellectual, political, technical, technological
- Liszt's piano music presents an enormous technical challenge
VERB + CHALLENGE
- be, pose, present
- face, meet, respond to, rise to, take on/ up
- The gallery has risen to the challenge of exhibiting the works of young artists. He has taken on some exciting new challenges with this job
CHALLENGE + VERB
- face sb
- the challenges facing nurses in casualty
ADJ
- serious
- direct
- effective
- legal
VERB + CHALLENGE
- be, present, represent
- The demonstration represents a direct challenge to the new law
PREP
- ~ to
- a legal challenge to the president's power
ADJ
- leadership, title
- his title challenge to the heavyweight champion
VERB + CHALLENGE
- issue, mount
- plans to mount a leadership challenge within the party
- accept, take up
- I accepted his challenge to a game of chess
- beat off, fight off
- Our team will have to fight off the challenge from better trained teams
PREP
- ~ from
- a challenge from the other political party
ADV
- directly
- The newspaper was directly challenging the government's legitimacy
- seriously
- effectively
- She was effectively challenging the whole basis on which society was run
- successfully
- The story was completely untrue and was successfully challenged in court
PREP
- on
- She challenged him on his old-fashioned views
ADV
- seriously
- No one has seriously challenged the champion
- successfully, unsuccessfully
PREP
- for
- She was poised to challenge for the party leadership
- to
- The count challenged him to a duel