Japanese seems to exist in a language family of its own, although some linguists believe it may be related to Korean and Turkish. It is spoken as a mother-tongue by the 130 million people in Japan and by expatriates across the world.
There are very significant differences between Japanese and English, particularly in sentence structure, which make it hard for most Japanese ESL students to acquire English at the same rate as, for example, their German or Swedish peers.
The Japanese writing system is complex. It uses three main scripts: Kanji (characters of Chinese origin), Hiragana (a syllabary) and Katakana (a syllabary). Modern Japanese also uses the Latin script in advertising, or for company names and neologisms such as DVD.
Traditionally, Japanese is written and printed in columns from top to bottom and from right to left. Books start 'at the back'. Modern Japanese is written or printed in the same order of words on the page as English.
Despite these differences, Japanese learners of English rarely have particular difficulties with English writing. Latin script (and English in particular) is encountered by most Japanese in their everyday life from an early age. It is also commonly used in romaji (the representation of the entire Japanese writing system in Latin script, used for example for computer keyboard input or to help non-native speakers learn the language).
Japanese has 5, pure vowel sounds that may be short or long. The syllable structure is simple, generally with the vowel sound preceded by one of approximately 15 consonant sounds. There are few complex consonant sound combinations such as in the English words strength or Christmas. As a result of these differences Japanese ESL students find English hard to pronounce, often insert short vowels between the consonants (ste-rength. Japanese learners of English may even have difficulty in correctly perceiving what they hear.
Specific problems with English vowel sounds include the failure to accurately render the dipthong in words such as caught/coat or bought/boat or the different vowel sound in minimal pairs such as hat/hut. The most noticeable problem rendering English consonants is seen in the inability of many learners to differentiate between the /l/ and the /r/ sounds. Words such as lot/rot or glimmer/glimmer are impossible for some of them to pronounce correctly. Unsurprisingly, Japanese learners also struggle with struggle with the (/θ/ /ð/) sounds, such as in the words month, thirteenth and clothes. The /v/ sound is also difficult for some, who say berry instead of very or ban instead of van.
The intonation patterns of Japanese and English do not have many features in common. Some of the meaning that the English native speaker conveys by stress and/or a change of pitch is differently expressed in Japanese (for example, by adverbials). Learners often benefit from explicit instruction and practice in these areas. In general, however, those learners who have had significant exposure to English and have become competent in it often acquire much more natural English prosody than, for example, Spanish or French with comparable levels of English proficiency.
Japanese tense and voice are conveyed through changes in the verb form, as in English. What is different is that Japanese has no auxiliary verbs, so, predictably, the formation of the progressive/perfect tenses and questions or negation in the simple tenses cause problems for learners. Japanese verbs do not change for person or number, the most common consequence of which is the omission of the -s in the present simple 3rd person: she go .. / my father work ...
Like most learners of English Japanese ESL students struggle to choose the correct tense to convey the intended meaning. As a brief example: Japanese learners may be tempted to use the present simple to convey future events, because this is how it is done in their own language (e.g., I help you after school.)
Differences in the circumstances in which English and Japanese use the passive and in the ways that it is constructed may result in sentences such as He was cut his hair or When were you come to Germany?
Japanese has a Subject-Object-Verb word order; 'prepositions' follow the noun and subordinating conjunctions follow their clause; other particles (for example, to express interrogation) follow the sentence. All adjectival phrases, no matter how long, precede the noun they modify. In all these aspects Japanese is different from English. Mistakes in the production of correct English syntax are not surprising, therefore.
The noun system in Japanese has features that can result in negative into English. Articles do not exist in Japanese. The fact that many Japanese nouns can also function as adjectives or adverbs leads to mistakes in the choice of the correct part of speech in English. Nouns can be pluralized in various ways (depending for example on the degree of respect to be conveyed) or not at all if the conetxt is clear. No distinction is made between countability and uncountability, which are extremely significant for the correct use of the article in English. It is little wonder that this aspect of English continues to cause difficulty to even the most proficient Japanese speakers of English.
There are numerous further small variations between Japanese and English which may interfere with the correct production of English. An example is the pronoun system. Relative pronouns do not exist in Japanese, and personal/possessive pronouns are used differently in the two languages. Mistakes such as the following are the result: new in school teacher (= the teacher who is new to the school) or He took off glasses and brushed hair.
A large number of English words are used in Japanese. This may help some learners with their acquisition of English vocabulary.
Many of the difficulties that Japanese learners have with English are not due to problems with the language itself but are more the result of cultural differences. Communication between any two people in Japan is heavily influenced by aspects such as age, sex, relationship and relative status. The Japanese generally have an aversion to assertiveness and seek to avoid embarrassment to themselves and their interlocutor. There is a respect for abstraction which is alien to many plain-speaking Westerners. All of this can cause Japanese learners to struggle to find the best way to express themselves and result in the production of English that native speakers may find excessively vague or tentative.