Belonging to the same language family, German is generally standardized.
German grammar is complicated, with many definite articles, many inflections and many inverted sentences. Nouns are feminine, masculine and neuter, which must be remembered at the same time. Learn pronunciation rules. German words themselves are phonetic symbols, which are easier to read. Generally, people who learn English first and then German will find it difficult to learn German because they think there are too many grammatical rules and parts of speech to memorize. On the other hand, I will find English difficult to learn, because I think the rules of English are irregular and it is not easy to draw inferences.
People who have studied are realistic, but they are not similar. German is quite complicated and difficult to learn. Without certain pressure, it is difficult to persist only by interest. The landlord should be careful in learning.
2. Japanese
The language family is controversial. Some people think it can be classified as Altaic language family, while some Japanese scholars think it is an isolated language, Fuyu language family or Japanese language family.
3. Thai is the Atai-Kadai language family (also called Zhuang-Dong language family, because China Zhuang-Dong language also belongs to this language family). Thai and Zhuang are fraternal languages of the same origin. Besides, Laotse is also the brother language of Thai and Zhuang.
Generally speaking, it should not be easily confused, but if there are too many kinds of learning, I personally think it will be general but not refined.