There are 5 rules that should help you determine whether a th should be voiced or voiceless. between two vowels th is voiced: mother, bother, weather, etc. at the end of the word or before a consonant, th is unvoiced: myth, mouth, mouthful, bath, truthful, throw, etc. when followed by a silent e, th is voiced.
Examples of Voiced and Unvoiced “TH”
The voiceless “th” sound is made without using vocal cords.
This sound is common in most words that begin with “th.” “Think,” “third,” and “thank” all start with the voiceless “th.” In the voiced “th,” English speakers use their vocal cords while they make the “th” sound.