Howe does 'th' sound in words

Th 

is a digraph.  That is when two letters make a new sound.  Th has two sounds one is voiced and the other is a whisper.  You have to put your tongue

between your teeth to make both sounds.   Check out this pic collage.  Say the words.  Can you tell what words have the voiced 'th' voiced and what ones have the whisper 'th'.