The spelling of the word "silna" can be explained using the International Phonetic Alphabet (IPA). The first sound is "s", which is pronounced "s" as in "sit". The second sound is "ɪ", which is pronounced "ih" as in "bit". The third sound is "l", which is pronounced "l" as in "light". The fourth sound is "n", which is pronounced "n" as in "net". Therefore, the word "silna" is pronounced as "sɪlnə" with emphasis on the first syllable.