My Word randomly capitalizes the letter "i" at the start of words, how do I get it to stop

Changing the font is what solved this problem for me. I suspect it could be to do with the mixed Mac/PC environment I was working in with some incompatibility on the PC with a font introduced on a Mac, or vice versa.

I was also frustrated by people telling me this fault could not be related to fonts because of <insert some technical explanation>. Changing the font solved it. Nothing else did. It's not for the users to explain why!

I apologize: for some reason, I thought you said that you wanted to convert "i" to "I." 

Which AutoCorrect options, if any, are available in Word when you run it on an iPad?

In Word for Windows (which this thread was originally about), AutoCorrect and AutoFormat As You Type can be configured in the AutoCorrect dialog box (File | Options | Proofing | AutoCorrect Options).

*grin* No worries - and I do appreciate your responding to my query.

Microsoft has not built those functions into Word for iOS (yet?) 

It does seem to use it's own text engine though, which would explain the weirdness with autocorrect & fonts. It's just interesting that this issue happens across different devices.

I apologize: for some reason, I thought you said that you wanted to convert "i" to "I." 

Which AutoCorrect options, if any, are available in Word when you run it on an iPad?

In Word for Windows (which this thread was originally about), AutoCorrect and AutoFormat As You Type can be configured in the AutoCorrect dialog box (File | Options | Proofing | AutoCorrect Options).

*grin* No worries - and I do appreciate your responding to my query.

Microsoft has not built those functions into Word for iOS (yet?) 

It does seem to use it's own text engine though, which would explain the weirdness with autocorrect & fonts. It's just interesting that this issue happens across different devices.

Thanks for the follow-up.

Unfortunately, Word for Mac devices is very different from Word for Windows devices (in some respects). Just in case, to get updated information, you may want to start a new thread in the Word for Mac section of this forum:

https://answers.microsoft.com/en-us/msoffice/forum/msoffice_word-mso_mac?sort=lastreplydate&dir=desc&tab=All&status=all&mod=&modAge=&advFil=&postedAfter=&postedBefore=&threadType=all&isFilterExpanded=true&tm=1533247053429

Use the Ask a Question link at the top right of the forums page.

Does anyone have a fix for this?  I have an end user who just brought this same problem to my attention.  If she types a word that begins with the letter i in the middle of a sentence, it capitalizes the I.   I am on an island becomes I am on an Island.   I'm going inside becomes I'm going Inside.  Our email address contains  agency.in.gov  it becomes  agency.In.gov

None of this is set up in autocorrect.  it's any word, anywhere in the sentence that begins with the letter i   

Any one have a suggestion?

Check which options for "predictive" text have been enabled for your operating system.