Pronunciation guide: IPA symbols, stress and word endings

θ	thin	ð	this	ʃ	she	ʒ	measure
tʃ	church	dʒ	judge	ŋ	sing	j	yes

p b t d k g f v s z h m n l r w sound as in ordinary English spelling.

ˈ main stress, before the stressed syllable: /ˈwɔːtə/ water · ˌ lighter (secondary) stress: /ˌʌndəˈstænd/ understand
ː a long vowel · (r) an r said only in accents that pronounce it (most American, Scottish, Irish)

-s / -es (plurals; he/she form of verbs): /s/ after voiceless sounds (cats), /z/ after voiced (dogs), /ɪz/ after s, z, sh, ch, j sounds (buses, watches). Spelling: -es after s, x, z, ch, sh; consonant + y → -ies (city → cities).
-ed (past): /t/ after voiceless sounds (walked), /d/ after voiced (played), /ɪd/ after t or d (wanted). Spelling: love → loved, stop → stopped, carry → carried.
-ing: make → making, run → running, see → seeing.
Irregular: go, went, gone · be, was, been · see, saw, seen · man → men · child → children · mouse → mice.
Older (King James) forms: -eth = -s (he loveth = he loves) · -est with “thou” (thou lovest) · spake = spoke.

teens

/tiːnz/ noun

Also a form of teen

noun The numbers between thirteen and nineteen (inclusive). “The number of people at the meeting was in the teens.”
noun The time of life between thirteen and nineteen years old; the teenage years. “She is in her teens.”
noun The second decade of a century: the 1910s, 2010s, etc. The oneties, the tens. “I was so excited for the teens to be over but then we get to the twenties and suddenly it's a pandemic!”
noun (temperature, rates) The range between 10 and 19. “Although it was a scorching desert by day, temperatures could drop as low as the teens at night.”

Etymology

The final syllable of the numbers from thirteen to nineteen. More at teen.

Etymology [See Ten.]

Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “teens”, CC BY-SA 4.0. Details