Pronunciation: [mˈə͡ʊst ˈə͡ʊldsɔː] (IPA)
Correct spelling for the English word "most oldsaw" is [mˈə͡ʊst ˈə͡ʊldsɔː], [mˈəʊst ˈəʊldsɔː], [m_ˈəʊ_s_t ˈəʊ_l_d_s_ɔː] (IPA phonetic alphabet).
Correct spelling for most oldsaw