Pronunciation exercises: /θ/ vs /s/

/θ/ is a dental consonant: the tongue is pressed against the upper teeth.

/s/ is a an alveolar consonant: the tongue touches the part of the mouth behind the upper teeth.

/θ/
Initial pronunciation of /θ/:
 * thanks, thing, think - thought

Final pronunciation of /θ/:
 * both, growth, health, month

Middle pronunciation of /θ/:
 * anything, everything, nothing, something
 * author, ethnic, healthy, mathematics

In English /sr/ can't be in the same syllable. People whose language lacks /θ/ may find it particularly difficult to pronounce /θr/
 * anthropology, arthritis, thread, threat, three, thriller, throat, throne, through, throw - threw

/θ/ and /r/ in different syllables
 * bathroom

/s/
Initial pronunciation of /s/:
 * same, say - said, school, see - saw, some, start

Final pronunciation of /s/:
 * course, house, less, place, this, yes,

Middle pronunciation of /s/:
 * also, lesson, next, person, receive

/θ/ vs /s/
Initial pronunciation
 * thank - sank (past tense of  sink); thin - sin; thing - sing; think - sink; thumb - sum;

Final pronunciation
 * bath /bæθ, bɑːθ/ - bass (fish) /bæs/; north - Norse; path - pass;

Variant pronunciations
The Spanish city of Zaragoza has the English name Saragossa /ˌsærəˈgɒsə/. Recently the Spanish name is used in English with the pronunciations /ˌzærəˈɡəʊzə, ˌsærəˈɡəʊsə/ or /ˌθærəˈɡəʊθə/.

Anticipated pronunciation difficulties
People with a lisp can't pronounce the sound /s/ and pronounce /θ/ instead.

Spanish L1
See IPA phoneme /θ/ § Latin_America.