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.

heartbeat

UK /ˈhɑːtˌbiːt/ · US /ˈhɑɹtˌbit/ noun

Forms heartbeats

noun One pulsation of the heart; especially an irregular one, hence the emotion which causes it. “The policeman waited for a heartbeat in vain.”
noun The rhythm at which a heart pulsates, a cardiac indicator. “If your heartbeat doesn't normalize soon, consult a doctor!”
noun A driving impulse or vital force; the vital center of something. “Music is the heartbeat of the people.”
noun A very short space of time; an instant. “The ambulance arrived in a heartbeat.”
noun (computing) A periodic signal generated by hardware or software to indicate normal operation or to synchronize other parts of a system.

Synonyms

From heart + beat.

Sources: Wiktionary · WordNet 3.0 — from the Wiktionary entry “heartbeat”, CC BY-SA 4.0. Details