 Hello, I am Mrs. Geetha Rinduwar, Assistant Professor of Communication Skills, Department of Humanities and Sciences, Walshchan Institute of Technology, Sholaku. We are discussing about the topic word formation mechanism in English grammar and this is the third part. So learning outcome at the end of this session student will be able to understand word formation mechanism effectively. Now in this session I will discuss about the last two word formation processes and that is derivation and back formation. So derivation, in linguistics derivation is the process of forming a new word from an existing words by adding a prefix or suffix. Derivation is the most common process of forming a new word by means of affixation. So let us first discuss what is the meaning of affixation. Take a pause, think about this question and try to give the answer. So affixation, affixation is linguistics process that speakers use to form different words by adding more films. At the beginning that is called as a prefixation in the middle that is called infixation or at the end that is suffixation. Affixation consists in adding derivational affixes to root words to form new words. They are classified according to the position or the function in the word or phrase. So derivation is accomplished by the use of affixes and these are the three types of affixes. So first one is prefix. Now we will discuss about what is prefixes. So prefixes are bound morphemes that are added in the beginning of a word. Prefix is an affix which is placed before the same of a word. Adding to the beginning of one word changes it into another word and the example is when the prefix un is added to the word happy it creates the word unhappy. These are some of the common prefixes that post martem or post script even we can use this pre, pro or sub. So these are the various examples of prefixes. Now see prefixes and their meaning the prefixes have their own meaning. So this chart it will show the meaning of the prefixes. So the example one example I will take it here un, un means not opposite of. So here I have given so many examples of prefixes and their meanings. So go through it. The second affixation is infixes. Infixes are inserted in the middle part of the word and are relatively rare in English but you can find them in the plural forms of some words. In the example is cup full or spoon full passer by. These words can be pluralized as cups full, spoons full and passers by. Here we are using s as an infix. Some combined words like mother in law by joining infixes we can do it as mothers in law. Here we are joining these affixes in the middle part. The third one is suffixes. A letter or group of letters that you add at the end of a word and that changes the meaning of the word or the way it is used is called a suffix. The examples are the original word is used and we are adding suffixes. So the word will be useful or useless. The second one is comfort. So comfortable we can add suffixes to this word and it is created as comfortable. So here are some of the words added by suffixes. So painful, fearful, then closeness, then quietness, sadly fearless, jobless. So these are the some of the examples of suffixes go through all these examples. In linguistics a suffix sometimes term postfix is an affix which is placed after the stem of a word. The common examples are case endings which indicate the grammatical case of nouns or adjectives and verb ending which form the conjugation of verbs. Now the suffixes and their meanings. So every suffix has their own meaning. So age that is the meaning is a result and the example is wreckage then and a person, assistant a n t. So all these are the suffixes, their meanings and these are the examples by adding suffixes. The next verb formation process is back formation. Back formation results when a word is formed from another word by taking off what looks like a typical affix in the language. It is a process of creating new forms by removing affixation from the existing words. In other words back formation is the opposite of derivation. So here are some of the examples of back formation. A noun enters the language first and then a verb is back formed from it and the examples are editor and the back formation is edit. The second example is diagnosis. From this word we have made the back formation, diagnose. Third example is television and the back formation is televised. Here are the more examples of back formation. The babysitter, babysit then donation, donate, gamble, gambler. So these are some of the examples of back formation. So go through all these examples. These are the references and I have used these references to create my PPT. So go through these references. Thank you once again. Thank you.