```python
def check_if_last_char_is_a_letter(txt):
    '''
    Create a function that returns True if the last character
    of a given string is an alphabetical character and is not
    a part of a word, and False otherwise.
    Note: "word" is a group of characters separated by space.

    Examples:
    check_if_last_char_is_a_letter("apple pie") ➞ False
    check_if_last_char_is_a_letter("apple pi e") ➞ True
    check_if_last_char_is_a_letter("apple pi e ") ➞ False
    check_if_last_char_is_a_letter("") ➞ False 
    '''
    if not txt:
        return False
    
    # Check if the last character is a letter
    if not txt[-1].isalpha():
        return False
    
    # Check if the last character is not part of a word
    # A word is a group of characters separated by space
    # So the last character should be preceded by a space (or be the only character)
    # If the last character is preceded by a space, it's not part of a word
    # If the last character is preceded by another character, it's part of a word
    
    # If the string has only one character, it's not part of a word (it's a single letter)
    if len(txt) == 1:
        return True
    
    # Check if the character before the last one is a space
    if txt[-2] == ' ':
        return True
    
    return False
```