A series of intermolecular complexes formed between the triatomic hydrides HAX and various interaction partners are investigated computationally aiming (1) to demonstrate that either an appearance or nonappearance of a blue shift of the A-H stretching frequency is directly related to the sign of the intramolecular coupling that exists between the two degrees of freedom, the A-H and A-X bond lengths, and (2) to offer the following conjecture: the theoretical protonation of a triatomic neutral molecule HAX at the site X is a simple and rather efficient probe of a red or blue shift that the stretching frequency nu(A-H) Undergoes upon complex formation regardless of whether this bond is directly involved in hydrogen bonding or not. In other words, to predict whether this A-H bond is capable to display a blue or red shift of nu(A-H), it Suffices to compare the equilibrium structures and vibrational spectra of a given molecule with its protonated Counterpart. The two above goals are achieved invoking a series of 11 triatomic molecules: HNO, HSN, HPO, and HPS characterized by a negative intramolecular coupling, HON and HNS as intermediate cases; and HOF, HOCl, HCN, HNC, and HCP with a positive intramolecular coupling. For these put-poses, the latter molecules are investigated at the MP2/6-311++G(2p,2d) level in the neutral and protonated HAXH(+) forms as well as their complexes with H2O and with the fluoromethanes H3CF, H2CF2, and HCF3.