The spelling of the word "schwalb" can be explained using the International Phonetic Alphabet (IPA) transcription. The word is pronounced as /ʃvɑːlb/. The first sound indicates the "sh" sound similar to "shirt." The following sound is a combination of "v" and "a" as in "valuable." The "-lb" at the end has a silent "b" sound and the final sound is a long "ah" like in "cart." Therefore, the correct spelling of this word uses the combination of the "sch" and "w" consonants, resulting in "schwalb."