The addition of a series of primary and secondary amides to the group 14 (di)metallenes Mes₂SiSiMes₂, Mes₂GeGeMes₂ and (Me₃Si)₂SiC(OSiMe₃)R, where R = t-Bu or R = 1-Ad, was examined. In general, the addition of primary and N-methyl amides gave amide adducts whereas the addition of N-phenyl amides gave imidate adducts. The regiochemistry of the additions was highly dependent upon the substituent bonded to the amide nitrogen. We propose that the formation of the adducts proceeds by way of a zwitterionic intermediate. The reactivity of tetramesityldigermene towards amides is used to predict the structure of the amide adducts formed on the Ge(100)-2 × 1 surface.