That would be, "I fink vat vat would be confusing", Froggie!

The soft 'th' (as in 'think' ) is mispronounced as an 'f'. The hard 'th' (as in 'that') would, if mispronounced at all, be pronounced as a 'v'. However, IME, many who mispronounce the soft 'th' do actually pronounce the hard 'th' correctly.

That's my observation anyway.