The spelling of "Costner" is influenced by phonetics. This word can be transcribed using the International Phonetic Alphabet (IPA) as /ˈkɒst.nər/. The first syllable is pronounced with an open O sound /ɒ/, followed by the consonant cluster /st/. The second syllable is pronounced with a schwa /ə/ sound, followed by the consonant /n/ and the vowel /ə/ again. This transcription provides a clear representation of the sounds that make up the name "Costner" and enables people to correctly spell and pronounce it.