Do you know about SUFFIXES?

A suffix goes at the end of a word. A prefix goes at the beginning

A suffix is a group of letters placed at the end of a word to make a new word. A suffix can make a new word in one of two ways:

1. inflectional (grammatical): for example, changing singular to plural (dog > dogs), or changing present tense to past tense (walk > walked). In this case, the basic meaning of the word does not change.
2. derivational (the new word has a new meaning, "derived" from the original word): for example, teach > teacher or care > careful

Inflectional suffixes

Inflectional suffixes do not change the meaning of the original word. So in "Every day I walk to school" and "Yesterday I walked to school", the words walk and walked have the same basic meaning. In "I have one car" and "I have two cars", the basic meaning of the words car and cars is exactly the same. In these cases, the suffix is added simply for grammatical "correctness". 

Look at these examples:

suffix	grammatical change	example original word	example suffixed word
-s	plural	dog	dogs
-en	plural (irregular)	ox	oxen
-s	3rd person singular present	like	he likes
-ed	past tense past participle	work	he worked he has worked
-en	past participle (irregular)	eat	he has eaten
-ing	continuous/progressive	sleep	he is sleeping
-er	comparative	big	bigger
-est	superlative	big	the biggest

Derivational suffixes

With derivational suffixes, the new word has a new meaning, and is usually a different part of speech. But the new meaning is related to the old meaning - it is "derived" from the old meaning.

We can add more than one suffix, as in this example:

derive (verb) + tion = derivation (noun) + al = derivational (adjective)

There are several hundred derivational suffixes. Here are some of the more common ones:

suffix	making	example original word	example suffixed word
-ation	nouns	explore hesitate	exploration hesitation
-sion		persuade divide	persuasion division
-er		teach	teacher
-cian		music	musician
-ess		god	goddess
-ness		sad	sadness
-al		arrive	arrival
-ary		diction	dictionary
-ment		treat	treatment
-y		jealous victor	jealousy victory
-al	adjectives	accident	accidental
-ary		imagine	imaginary
-able		tax	taxable
-ly		brother	brotherly
-y		ease	easy
-ful		sorrow forget	sorrowful forgetful
-ly	adverbs	helpful	helpfully
-ize	verbs	terror private	terrorize privatize
-ate		hyphen	hyphenate

Note that the suffix -er can convert almost any verb into the person or thing performing the action of the verb. For example: a teacher is a person who teaches, a lover loves, a killer kills, an observer observes, a walker walks, a runner runs; a sprinkler is a thing that sprinkles, a copier copies, a shredder shreds.