The function takes a string input and returns the length of the string as an English word, with vowels shifted one position forward in the alphabet, and consonants shifted one position backward in the alphabet.

[CODE]: 
```python
def shifted_length_word(input_string):
    length = len(input_string)
    NUMBER_NAMES = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"]
    word = NUMBER_NAMES[length]

    shifted_word = ""
    for char in word:
        if char in "aeiou":
            shifted_char = chr(((ord(char) - ord('a') + 1) % 26) + ord('a'))
        else:
            shifted_char = chr(((ord(char) - ord('a') - 1) % 26) + ord('a'))
        shifted_word += shifted_char

    return shifted_word

print(shifted_length_word("hello"))
print(shifted_length_word("world"))
print(shifted_length_word("test"))
```

Please note that this code is only an approximation of the function's behavior, and might not cover all edge cases.