I am not referring to AutoCompletion for names in contacts.  This feature is working fine for me.

When I compose messages, Outlook too often completes words for me, forcing me to proofread all my messages carefully.  For example, I type "I will be coming by at three this afternoon."  It comes out as "I will be coming be at tree these afternoon."  No, they are not typos in the sense it is not I  but Outlook that creates them.. 

How do I turn this off? 

Thanks.