One who recites Kaddish must ensure while saying the phrase "Be'alma Di Bera" to pronounce "Di Bera" as two separate words. If one recites this phrase too quickly, he will end up saying, "Dibera," as one word, which is incorrect. He must be careful to recite two separate words – "Di" and "Bera."
Different opinions exist regarding the pronunciation of the word "Chi'r'uteh" in the phrase "Be'alma Di Bera Chi'r'uteh," as according to some views, the letter Chaf has a Dagesh (dot), such that it should be pronounced "Ki'r'uteh." The debate hinges on how to read this phrase. The basic rule is that when any of the letters Bet, Gimmel, Dalet, Kaf, Peh or Tav appears at the beginning of the word, it receives a Dagesh. The exception to this rule is when the preceding word ends with an Alef, Heh, Vav or Yod, in which case the word does not receive a Dagesh. In the case of "Chi'r'uteh," then, it would seem that since the previous word ("Bera") ends with the letter Alef, the Chaf at the beginning of "Chi'r'uteh" should remain without a Dagesh, and thus be pronounced "Chi'r'uteh." Indeed, this is how the word is punctuated in many editions of the Siddur.
However, Hacham Ovadia Yosef ruled that the more correct pronunciation is "Ki'r'uteh." He explained that although the previous word ends with an Alef, that word – "Bera" – is not connected to the word "Ki'r'uteh." The word "Ki'r'uteh" means "in accordance with His will," and Hacham Ovadia explained, based on a passage in Masechet Sofrim, that this word modifies not the immediately preceding words, but rather the beginning of Kaddish, when we pray for G-d's Name to be glorified. We pray that His Name should be sanctified and praised "Ki'r'uteh" – in fulfillment of His will. Hence, the word "Ki'r'uteh" stands separate and apart from the words "Di Bera," and so the Heh at the end of the word "Bera" does not affect the letter Chaf at the beginning of the word "Ki'r'uteh." We thus apply the standard rule that a Chaf at the beginning of a word receives a Dagesh, such that the word should be pronounced "Ki'r'uteh."
Rav Meir Mazuz (1945-2025) disputed Hacham Ovadia's position. He noted that the Abudarham (Spain, 14th century) interpreted "Di Bera Chi'r'uteh" to mean, "that He created in accordance with His will." According to this reading, the word "Chi'r'uteh" indeed modifies the immediately preceding words – "Di Bera," such that the letter Chaf should not receive a Dagesh. Rav Mazuz conceded, however, that the passage in Masechet Sofrim indeed implies that "Chi'r'uteh" modifies the earlier part of the sentence, and not the words "Di Bera."
In practice, different customs exist. Tunisian communities pronounce the word "Ki'r'uteh," whereas the custom among the communities in Aleppo, Syria was to pronounce it "Chi'r'uteh." Rav Yisrael Bitan writes that Hacham Ovadia, despite preferring the pronunciation of "Ki'r'uteh," acknowledged that those who pronounce it "Chi'r'uteh" have a legitimate basis for this practice. Therefore, each community should follow its custom.
Summary: One who recites Kaddish must ensure while saying the phrase "Be'alma Di Bera" to pronounce "Di Bera" as two separate words, and not as one word ("Dibera"). Different customs exist regarding the next word – "Chi'r'uteh," as some pronounce the word this way, and others pronounce it "Ki'r'uteh." Each community should follow its custom.