A word starting with a capital letter is usually accepted as correctly spelt if it is correctly spelt with the form starting with a lower case letter. For example, in English only 'activate' and 'deactivate' might be in the dictionary, but 'Activate' and 'Deactivate' is accepted. This is important for handling the first word in sentences.
This test case however is not working as expected:
PFX a Y 1
PFX a u no u
Word correctly accepted: