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.

optimism

UK /ˈɒptɪmɪzəm/ · US /ˈɑptɪmɪzəm/ noun

Forms optimisms

noun A tendency to expect the best, or at least, a favourable outcome. “I love her youth, her beauty and above all her optimism that everything will turn out fine.”
noun The doctrine that this world is the best of all possible worlds.
noun The belief that good will eventually triumph over evil.

Antonyms

From French optimisme, equivalent to Latin optimus + -ism.

noun The opinion or doctrine that everything in nature, being the work of God, is ordered for the best, or that the ordering of things in the universe is such as to produce the highest good.
noun A disposition to take the most hopeful view; --opposed to pessimism.

Etymology [L. optimus the best; akin to optio choice: cf. F. optimisme. See Option.]

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