The dictionary should be consulted whenever there is any doubt.
If you are to write a word, call up a mental picture of it, and if the picture is not perfectly clear go to the dictionary and fix a correct image of it in your mind.

Be careful to pronounce every word you use as correctly as possible and you will get all the aid pronunciation can give you.
Careless speaking and careless reading are the two great sources of incorrect spelling.
The following tables will be found useful in settling practice with regard to certain troublesome classes of words.
I American usage tends to the termination _-ize_ where English usage often sanctions _-ise_.

Use the termination _-ise_ in advertise advise appraise apprise (_to inform_) arise chastise circumcise comprise compromise demise devise disfranchise disguise emprise enfranchise enterprise exercise exorcise franchise improvise incise merchandise premise reprise revise rise supervise surmise surprise Use the termination _-ize_ or _-yze_ in aggrandize agonize analyze anatomize anglicize apologize apostrophize apprize (_to value_) authorize baptize brutalize canonize catechize catholicize cauterize centralize characterize christianize civilize colonize criticize crystallize demoralize dogmatize economize emphasize epitomize equalize eulogize evangelize extemporize familiarize fertilize fossilize fraternize galvanize generalize gormandize harmonize immortalize italicize jeopardize legalize liberalize localize magnetize memorialize mesmerize metamorphize methodize minimize modernize monopolize moralize nationalize naturalize neutralize organize ostracize paralyze particularize pasteurize patronize philosophize plagiarize pulverize realize recognize reorganize revolutionize satirize scandalize scrutinize signalize solemnize soliloquize specialize spiritualize standardize stigmatize subsidize summarize syllogize symbolize sympathize tantalize temporize tranquilize tyrannize universalize utilize vaporize vitalize vocalize vulcanize vulgarize II Use the termination _-ible_ in the following words: accessible admissible appetible apprehensible audible cessible coercible compatible competible comprehensible compressible conceptible contemptible contractible controvertible convertible convincible corrigible corrosible corruptible credible decoctible deducible defeasible defensible descendible destructible digestible discernible distensible divisible docible edible effectible eligible eludible enforcible evincible expansible expressible extendible extensible fallible feasible fencible flexible forcible frangible fusible gullible horrible illegible immiscible impassible intelligible irascible legible miscible negligible partible passible (_susceptible_) perceptible permissible persuasible pervertible plausible possible producible reducible reflexible refrangible remissible reprehensible resistible responsible reversible revertible risible seducible sensible tangible terrible transmissible visible In all other cases use _-able_.
III The following nouns end in _-er_.
abetter abstracter accepter adapter adviser affirmer aider almoner annoyer arbiter assenter asserter bailer caster censer (vessel) concocter condenser conferrer conjurer consulter continuer contradicter contriver convener conveyer corrupter covenanter debater defender deliberater deserter desolater deviser discontinuer disturber entreater exalter exasperater exciter executer (_except in law_) expecter frequenter granter idolater imposer impugner incenser inflicter insulter interceder interpreter interrupter inviter jailer lamenter mortgager (_except in law_) obliger obstructer obtruder perfecter perjurer preventer probationer propeller protester recognizer regrater relater respecter sailer (_ship_) sorcerer suggester supplanter upholder vender The following nouns end in _-or_.
abbreviator abductor abettor (_law_) abominator abrogator accelerator acceptor accommodator accumulator actor adjudicator adjutor administrator admonitor adulator adulterator aggregator aggressor agitator amalgamator animator annotator antecessor apparitor appreciator arbitrator assassinator assessor benefactor bettor calculator calumniator captor castor (_oil_) censor coadjutor collector competitor compositor conductor confessor conqueror conservator consignor conspirator constrictor constructor contaminator contemplator continuator contractor contributor corrector councillor counsellor covenantor (_law_) creator creditor cultivator cunctator debtor decorator delator (_law_) denominator denunciator depredator depressor deteriorator detractor dictator dilator director dissector disseizor disseminator distributor divisor dominator donor effector elector elevator elucidator emulator enactor equivocator escheator estimator exactor excavator exceptor executor (_law_) exhibitor explorator expositor expostulator extensor extirpator extractor fabricator factor flexor fornicator fumigator generator gladiator governor grantor (_law_) habitator imitator impostor impropriator inaugurator inceptor incisor inheritor initiator innovator insinuator institutor instructor interlocutor interpolator interrogator inventor investor juror lector legator legislator lessor mediator modulator monitor mortgagor (_law_) multiplicator narrator navigator negotiator nonjuror numerator objector obligor (_law_) observator operator originator pacificator participator peculator percolator perforator perpetrator persecutor perturbator possessor preceptor precursor predecessor predictor prevaricator procrastinator procreator procurator professor progenitor projector prolocutor promulgator propagator propitiator proprietor prosecutor protector protractor purveyor recognizor (_law_) recriminator reflector regenerator regulator relator (_law_) rotator sacrificator sailor (_seaman_) scrutator sculptor sectator selector senator separator sequestrator servitor solicitor spectator spoliator sponsor successor suitor supervisor suppressor surveyor survivor testator tormentor traitor transgressor translator valuator vendor (_law_) venerator ventilator vindicator violator visitor IV Words which in their shortest form end in _-d_, _-de_, _-ge_, _-unit_, _-rt_, _-se_, _-sr_, take the ending _-sion_; e.g., _abscind_, _abscission_; _include_, _inclusion_; _emerge_, _emersion_; _remit_, _remission_; _infuse_, _infusion_; _repress_, _repression_.
All others take the ending _-tion_.
The following are irregularities: adhesion assertion attention coercion cohesion crucifixion declension dimension dissension distortion divulsion expulsion impulsion insertion intention occasion propulsion recursion repulsion revulsion scansion suspicion tension version Words ending in _-ance_, _-ence_; _-ancy_, _-ency_; _-ant_, and _-ent_, often cause confusion when carelessly written.
The following is a list of the more common words with the _e_ form.
abducent abhorrence, -ent abluent absent, -ence absorbent abstergent abstinence, -ent adherence, -ent advertency, -ent affluence, -ent antecedence, -ent apparent appertinent appetence, -ency ardent benevolence, -ent circumference coexistence coherence, -ent coincidence, -ent competence, -ent concurrence, -ent condolence conference confidence, -ent confluence, -ent consentient consequence consequent consistence, -ent consistency constituent continence, -ent convenience, -ent corpulence, -ent correspondence, -ent currency, -ent deference delinquency, -ent dependence, -ent deponent descendent (_adj._) despondency, -ent difference diffidence, -ent diffluent efficiency, -ent eminence, -ency eminent excellence, -ency excellent existence, -ent expediency feculence, -ent flocculence, -ent fluency, -ent fraudulence, -ent imminence, -ent impatience, -ent impellent imprudence, -ent impudence, -ent incipience, -ent incumbency, -ent independence, -ent indolence, -ent inference inherence, -ent intermittent iridescence, -ent lambent latency, -ent leniency, -ent magniloquence, -ent malevolence, -ent mellifluence, -ent mollient obedience, -ent occurrence, -ent omniscience, -ent opulence, -ency opulent patience, -ent pendent (_adj._) pendency penitence, -ent permanence, -ent permanency pertinence, -ent pestilence, -ent poculent portent potency, -ent precedence, -ent preference prescience, -ent presence, -ent presidency, -ent proficiency, -ent prominence, -ent proponent providence, -ent prudence, -ent purulence, -ent quintessence recurrence, -ent reference refluence, -ent repellent residence, -ency resident resolvent resplendence, -ent respondent reverence, -ent sentient solvency, -ent somnolency, -ent subserviency, -ent subsidence, -ency subsistence, -ent succulent superintendence superintendency superintendent tendence, -ency transcendence, -ent transcendency transference transient transparency, -ent transplendency, -ent turbulence, -ent vicegerency, -ent virulence, -ent Nearly all other words of this type take the _a_ form.
* * * * * The instructor should drill the pupils in spelling not only these "catch" words, but a wide range of English words.

These lessons may be taken to advantage from some of the books mentioned in the list for supplementary reading, from any other good spelling book, or even from the pages of any well printed book or magazine.

The words should be given out orally and written down by the pupil.