For example: clip
"I clipped some extensions into my hair to make it look more voluminous."
"I went to the hairdressers who clipped an inch off of my overgrown hair."
In the first sentence, clip means 'attach', whilst in the second, it means 'removed'. Another example is dust.
"My mother-in-law was coming for dinner, so I dusted the shelves."
"I murdered my mother-in-law, so the police dusted the shelves for fingerprints."
Again, the two sentences have very different meanings. In the first, dust was removed, in the second, it was added.
So, just a short update for now. Hasta luego, mis amigos...