People often ask which is the most difficult language to learn, and it is not easy to answer because there are many factors to take into consideration.

Firstly, in a first language, the differences are unimportant as people learn their mother tongue naturally, so the question of how hard a language is to learn is relevant when learning a second language.

A native speaker of Spanish, for example, will find Portuguese much easier to learn than a native speaker of Chinese, for example, because Portuguese is very similar to Spanish, while Chinese is very different, so the first language can affect learning a second language. The greater the differences between the second language and our first, the harder it will be for most people to learn. Many people answer that Chinese is the hardest language to learn, possibly influenced by the thought of learning the Chinese writing system, and the pronunciation of Chinese does appear to be very difficult for many foreign learners. However, for Japanese learners, who already use Chinese characters in their own language, learning writing will be less difficult than for learners of languages using Roman alphabets. Some people seem to learn languages readily, while others find it very difficult. Teachers and the circumstances in which the languages are learned also play an important role, as well as each learner's motivation for learning. If people learn a language because they need to use it professionally, they often learn it faster than the people studying a language that has no direct use in their day-to-day life.

Apparently, British diplomats and other embassy staff have found that the second hardest language is Japanese, which will come as no surprise to many, but the language that they have found to be the most problematic is Hungarian, which has 35 cases. This does not mean that Hungarian is the hardest language to learn for everyone, but it causes British diplomats, who are generally used to learning languages the most difficult. However, Tabassaran, language has 48 cases, so it might cause more difficulty if the British had to learn it. Different cultures and individuals from those cultures will find different languages more difficult. In the case of Hungarian for British learners, it is not a question of the writing system, which has a similar alphabet, but the grammatical complexity, though native speakers of related languages may find it easier while struggling with languages that the British find relatively easy.
                                                     
No language is easy to learn well, though languages which are related to our first language are easier. Learning a completely different writing system is a huge challenge, but that does not necessarily make one language more difficult than another. In the end, it is impossible to say that there is one language that is the most difficult language in the world.