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.

act on

verb

Forms acts on acting on acted on

verb To act decisively on the basis of information received or deduced. “The policeman decided to act on the tip from his informant.”
verb To act accordingly to a (usually sublimated) desire or impulse. “He keeps telling me about wanting to make a move, but he hasn't worked up to acting on it yet.”
verb To take action against something. “World leaders have repeatedly stated that we must act on climate change.”
verb (medicine) To affect something. “Different drugs act on different parts of our body in many different ways.”
verb Used other than figuratively or idiomatically: see act, on.

Synonyms

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