This false friend thing is amazing. The more you think you know, the more you find out, and some you just get to take for granted. This is true of that pair of false friends “punctual” and “puntual”. I was reminded of the difference today listening to a news report about “un problema puntual” which means an occasional, “one-off” problem. “Puntual” in Spanish can also carry the same meaning as English, but is more often used to mean “occasional”.
The most common phrase I’ve heard referring to our idea of punctuality is “la puntualidad inglesa” which I get accused of displaying when I arrive only five minutes late for a meeting instead of the standard half an hour.