English is a West Germanic language that was first spoken in early medieval England and rose to become the Lingua Franca of the 21st century. It is named after the Angles, one of the ancient Germanic peoples, who migrated to an area of Great Britain, that later took their name, England. Both names are derived from Anglia, a peninsula on the Baltic Sea. While English is most closely related to Frisian and Low Saxon(courtesy the Anglo-Saxon settlers of the 5th and 7th centuries), its vocabulary has been significantly influenced by other Germanic languages, particularly Old Norse (a North Germanic language predominantly spoken by the Vikings), as well as Latin and French.
Japanese, on the other hand, is classed as an isolated language. However, current study on proto-Japanese reveals links to other Southeast Asian languages. As a result, linguists frequently classify Japanese as member of the Austric-family as Para-Austronesian.
When it comes to classifying the similarities and differences between English and Japanese, the differences far outweigh the similarities in terms of sentence structure, greetings, vocabulary, and writing.

While both languages have many similarities, such as Katakana and hiragana being phonetic systems that share the same sounds, katakana is mostly employed for foreign loan words. The letters in these two systems are similar to those in the English alphabet in that they represent phonetic sounds and are subsequently joined to form words.
Japanese also has honorific suffixes which are similar to Mr., Mrs., Ms. in English but are much more varied, such as -kun (くん), -chan (ちゃん), -san (さん), -sama (さま). Where Mr., Mrs., Ms. are considered around the same politeness level, -kun is normally used when someone of higher rank addresses a younger man or child, -chan for young girls and children, -san is the general Japanese equivalent of Mr., Mrs., Ms., and -sama is a very respectful honorific and is often used in business as well as when referring to Japanese deities (kami-sama 神様).
There are also many Japanese vocabulary words/phrases that do not have an exact English equivalent, for example otsukaresama (お疲れ様). Otsukaresama literally means “you’re tired” but it’s a common phrase used when saying goodbye to co-workers at the end of the day meaning “I’m really grateful for your hard work.”
Another expression that is firmly established in Japanese society is yoroshiku onegaishimasu (よろしくお願いします). This sentence might have several meanings depending on the situation. After meeting someone for the first time and exchanging self introductions, say yoroshiku onegaishimasu, which translates as “glad to meet you!” When used in a commercial advertisement following the announcement of a product release date, yoroshiku onegaishimasu takes on the meaning of “please purchase our product.”

As you can see, Japanese is a very contextual language, and it needs a professional, experienced translator to assist capture the proper meaning while translating to or from Japanese. Thus, English can only offer a helping hand while studying Japanese because they are essentially two separate languages from two different language families, with far more significant differences that render them incomprehensible than simple similarities.
The sentence structure in Japanese is SOV (Subject-Object-Verb), whereas in English it is SVO (Subject-Verb-Object). Anything in spoken Japanese can be removed from entire phrases if it still makes sense. As a result, it is a relatively simple language to learn from the beginning. Instead of stating “I’d like to drink milk” in English, you might just say “Milk” in Japanese. In addition, written Japanese is known for its long-winded sentences, where a single Japanese phrase can constitute a paragraph. Remember that similarity does not imply that the language will be easy to learn unless it fits into the same language group. And there are four levels of English and Japanese available.
FSI classifies Japanese to be a part of its Category V languages that are classified as the toughest languages for an English speaker to master until CEFR B2 level. Additionally, learning Japanese requires that an English speaker, invest 88 guided weeks or 2200 guided hours and an equal number of hours more with self-practice! So I really see no way how English is any value add to learn Japanese!
