Form:-

Program:-

Public Class slip11

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim n As String

        Dim count As Integer

        n = TextBox1.Text

        For i As Integer = 0 To n.Length - 1

            If " " = n(i) Then

                count = count + 1

            End If

        Next

        count = count + 1

        MsgBox("Total words in sentence: " + CStr(count))

    End Sub

End Class

Output:-

1) Take  Textbox, Label, Button on Design form.

2) Set text on label and button.

Note - Set startup form's application type as Windows Form Application