Sounds the same - how to tell the difference?

Par dessus - on top Par dessous - underneath These sound the same, so in conversation how do I tell the difference? They actually mean the opposite.Je confuse. Merci.

They're actually pronounced differently so *can* tell them apart, so this is more like a "train your ear" suggestion. "Dessous" is pronounced like "de-soo" with hardly any aspiration at the end. "Dessus" is more like "de-seuw(h)" and the aspiration is more pronounced at the end.

I agree; it comes with practice and ear training, in the same manner as we learned the English sounds. Think for a minute about the words: poor, pure, pour. Their spellings and their pronounciations are similar, yet their meanings are very different. One thing that helps, even native speakers, is context. For example, we may hear, "La plate est par dessus la table," or we hear, "Le chien est par dessous la table." In these two situations, it's evident which means on top of and which means underneath the table.