Depends on your native language there are harder and easier languages for sure. It is much easier for a Chinese to read and understand Japanese comparing to som

Depends on your native language there are harder and easier languages for sure. It is much easier for a Chinese to read and understand Japanese comparing to someone who don't know the symbols and need to learn it from scratch. It is easier to learn other languages from the same group, like learning a different latin language, germanic language or semitic language if you know one of them already. There are other factors also like similarities in grammatical structure, in variations of the language around situations which require more politeness or formality like in Japanese, written vs. spoken language like in Arabic and many other factors.