Spelling is the writing of a word or words with the necessary letters and diacritics present in an accepted standard order. Pronunciation changes over time in all languages, yet spelling is irregular in most languages and rare in some. Spelling is important because it aids reading. It helps cement the connection that is shared between letters and sounds.
There are many rules of spellings. Most nouns make their plurals by simply adding –s to the end (e.g. cat - cats, book – books, etc.). If the noun ends with -ch, -s, -sh, -x, or -z, then -es is added to form the plural. Many adverbs are formed from adjectives and end in -ly. The suffix -ful can form nouns or adjectives, like plateful or cheerful. People sometimes make the mistake of spelling this type of word with a double ‘l’ at the end. If the verb has only one syllable and ends with a single vowel plus a consonant, then you need to double the final consonant before adding -ed and –ing.