Which are the world’s most efficient languages?

It's challenging to determine the "most efficient" language when speaking because efficiency can be subjective and dependent on various factors. However, some languages are often considered more efficient due to their grammar, word order, and conciseness. Here are a few languages that are generally regarded as efficient in terms of spoken communication: 

1. Mandarin Chinese: Mandarin Chinese is known for its relatively concise grammar and sentence structure. It conveys a lot of information in a short amount of time due to its use of tones and context-based meaning. 
2. Japanese: Japanese is another language that tends to be efficient due to its use of particles, which indicate grammatical relationships between words. Additionally, Japanese often omits subjects when they're clear from the context, making conversations more streamlined.
3. Spanish: Spanish is known for its straightforward grammar and phonetic spelling, which makes it easy to learn and speak. Its sentence structure is usually subject-verb-object, which can contribute to efficiency in communication.
4. German: German is often considered efficient because it allows for the creation of compound words, enabling speakers to express complex ideas in a single word. It also has a consistent grammatical structure and word order.
5. Finnish: Finnish is known for its agglutinative nature, where words are formed by adding affixes to the root. This allows for the creation of precise and concise expressions, making it efficient in conveying information.

It's important to note that efficiency in spoken communication can vary depending on the context, speaker's fluency, and personal preferences. Different languages have different strengths and weaknesses, and what may be considered efficient for one purpose or culture may not be the same for another.