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.

derail

UK /ˌdiːˈɹeɪl/ · US /ˌdiˈɹeɪl/ noun, verb

Forms derails derailing derailed

noun Synonym of derailer: A device placed on railway tracks in order to cause a train to derail. “The derail was placed deliberately so that the train would fall into the river.”
noun An instance of diverting a conversation or debate from its original topic.
verb (transitive) To cause to come off the tracks. “The train was destroyed when it was derailed by the collision.”
verb (intransitive) To come off the tracks.
verb (intransitive, figurative) To deviate from the previous course or direction. “The conversation derailed once James brought up politics.”
verb (transitive, figurative) To cause to deviate from a set course or direction. “The protesting students derailed the professor's lecture.”

Synonyms

From French dérailler (“to go off the rails”). Analyzable as de- + rail.

Sources: Wiktionary · WordNet 3.0 · Webster’s 1913 — from the Wiktionary entry “derail”, CC BY-SA 4.0. Details