Would Have Overcome or Overcame?

You are quite right that the past tense of 'overcome' is 'overcame', by the way it follows the same form as the verb 'to come' – 'come','came' – the simple past, and 'come' the past participle.

Is it have overcome or have overcame?

Word forms: overcomes, overcoming, overcamelanguage note: The form overcome is used in the present tense and is also the past participle. If you overcome a problem or a feeling, you successfully deal with it and control it. Molly had fought and overcome her fear of flying.

How do you use overcame in a sentence?

1 He overcame a strong temptation to run away. 2 She overcame injury to win the Olympic gold medal. 3 Juventus overcame Ajax in a thrilling match. 4 His conscience overcame him and he restored the books he had taken from the shop.