Pronunciation: [lˈɛtɪŋ əpˌɒn] (IPA)
Correct spelling for the English word "letting upon" is [lˈɛtɪŋ əpˌɒn], [lˈɛtɪŋ əpˌɒn], [l_ˈɛ_t_ɪ_ŋ ə_p_ˌɒ_n] (IPA phonetic alphabet).
Correct spelling for letting upon