The ControlType property, e.g.:
Forms!Form1!Text0.ControlType
You can interpret the number returned with this function:
Function ControlTypeName(n As Long) As String
'Purpose: Return the name of the ControlType.
'Note: The ControlType returns a Byte, but the constants are Long.
Dim strReturn As String
Select Case n
Case acBoundObjectFrame
strReturn = "Bound Object Frame"
Case acCheckBox
strReturn = "Check Box"
Case acComboBox
strReturn = "Combo Box"
Case acCommandButton
strReturn = "Command Button"
Case acCustomControl
strReturn = "Custom Control"
Case acImage
strReturn = "Image"
Case acLabel
strReturn = "Label"
Case acLine
strReturn = "Line"
Case acListBox
strReturn = "List Box"
Case acObjectFrame
strReturn = "Object Frame"
Case acOptionButton
strReturn = "Object Button"
Case acOptionGroup
strReturn = "Option Group"
Case acPage
strReturn = "Page (of Tab)"
Case acPageBreak
strReturn = "Page Break"
Case acRectangle
strReturn = "Rectangle"
Case acSubform
strReturn = "Subform/Subrport"
Case acTabCtl
strReturn = "Tab Control"
Case acTextBox
strReturn = "Text Box"
Case acToggleButton
strReturn = "Toggle Button"
Case Else
strReturn = "Unknown: type" & n
End Select
ControlTypeName = strReturn
End Function