(Despite the commitment and energy you show in striving to help people to believe,) those who willfully persist in unbelief: it is alike to them whether you warn them or do not warn them; (although it is your mission to warn them and you do it without any neglect,) they will not believe
As for those who have chosen denial in advance (because of blind following, arrogance, peer pressure and self-interest), it does not matter whether you admonish them or not
As far as the disbelievers are concerned, in spite of your (Mohammad’s) warning, they do not care at all and they will never believe [in submission to the will of God.]
Faridul Haque
As for those whose fate is disbelief, whether you warn them or do not warn them - it is all one for them; they will not believe. (Because their hearts are sealed - see next verse)
Hasan Al-Fatih Qaribullah
Those who disbelieve, whether you forewarn them or not, they will not believe
As for those who are bent upon denying (the truth), they would not believe, because it is all the same to them whether you warn them or do not warn them
Indeed, for those who deny (cover) the reality, it is all the same whether you warn them or do not warn them – they will not believe.
Sayyed Abbas Sadr-Ameli
Surely, (as for) those who reject Faith, it is the same to them whether you have warned them or have not warned them, they will not believe
Al-muntakhab fi tafsir al-Qur'an al-Karim
As to those who deny Allah, not lifting to Him their inward sight, it is all the same to them whether you warn them O Muhammad of menacing danger and misfortune or not