English thankful

← Old English þancful (inherited)

← Old English þancfull (mention)

← English thank (suffix)

← English ful (suffix)

← Middle English thankful (inherited)

← Old High German undankfol (cognate)

→ English -ful (link)

→ English thankfulness (suffix)

→ English thankfully (suffix)

→ English unthankful (prefix)