TextRange Characters, Words, Sentences, Runs Paragraphs, Font Bold, Underline Italic ( ). :
Sub setTextDetails()
Dim tr As TextRange
Set tr = ActiveWindow.Selection.SlideRange.Shapes(1).TextFrame.TextRange
With tr
.Text = "Hi There Buddy!"
.Words(1).Font.Bold = msoTrue
.Runs(1).Font.Italic = msoTrue
.Paragraphs(1).Font.Underline = msoTrue
End With
End Sub