IPA phoneme /θ/
In English, both in Received Pronunciation and in General American, the IPA phonetic symbol /θ/ corresponds to the initial consonant sound in words like "think", and "thought" and the final one in "bath" and "both".
 Common words
Initial pronunciation of /θ/:
- thanks - theatre - theme - thin - thing - think - thirteen - thirty - thorough - thought - thousand - threat - threw/through - throw - thumb - Thursday;
Final pronunciation of /θ/:
- bath - both - earth - math(s) - path - teeth - tooth;
 Anticipated pronunciation difficulties depending on L1
Preconceived ideas and other interferences from L1 obviously interfere in many cases with how students perceive - and pronounce - sounds/words in English. The following section aims to point out some of the most typical difficulties teachers and students may encounter regarding pronunciation.
Many speakers don't distinguish clearly between /θ/ and /ð/ and when they see "th" tend to pronounce it [θ], a sound which corresponds to the letter "z" in Spanish. This happens also when speaking Spanish: Madrid's inhabitants are notorious for pronouncing [ma'driθ].
Another difficulty is the tendency to pronounce the initial letter "c" as /θ/ in words like "city" and "centre".
 Latin America
The /θ/ sound doesn't exist, and speakers tend to replace it by /s/ or /t/.