Quote 1
"'No!' she [the Intended] cried. 'It is impossible that all this should be lost – that such a life should be sacrificed to leave nothing - but sorrow. You know what vast plans he had. I knew of them, too – I could not perhaps understand - but others knew of them. Something must remain. His words, at least, have not died.'
'His words will remain,' I said." (3.68-69)
Words, it is suggested, are the only things that remain forever, that can capture memory and not fade away into nothingness.
Quote 2
"'[…] Who was not his friend who had heard him speak once?' she (the Intended) was saying. 'He drew men towards him by what was best in them.' She looked at me with intensity. 'It is the gift of the great,' she went on […]." (3.61)
The Intended puts great store by Kurtz’s words, believing that they lured men to him and earned him his admiration from all mankind. She is naïve about the true motivations of men which are often far darker and more self-serving.
Quote 3
[The Intended]: "‘I feel I can speak to you - and oh! I must speak. I want you – you who have heard his last words – to know I have been worthy of him. […] It is not pride. […] Yes! I am proud to know I understood him better than any one on earth – he told me so himself.’" (3.59)
The Intended equates speaking with understanding, begging Marlow to speak to her of Kurtz because he was one of the few who understood him as she did.