I judge efficiency by how many words and letters it takes to convey a message. I notice that in multi-lingual signs and instruction books some languages take more space to say something than others. English is generally one of the shortest because it contains a lot of simple one symbol words- where Spanish, for example has mostly multi-syllable words. For example- we say “boy”- 3 letters- in Spanish- “muchacho”- 8 letters. And Spanish has unnecessarily complex grammar rules with a multitude of verb forms and gender-specific adjectives. Just no need for such complexity.