 In the literature the terms morphological processes and morphological operations have not been used in a uniform way. Some linguists even contradict each other. In our approaches to words and word structure, these two aspects of morphology are strictly kept apart. We define morphological operations as to how words can be modified i.e. by the addition of new material by changing existing material etc. In the following, we will outline, discuss and exemplify the central morphological operations in present-day English and in other languages. Morphological operations manipulate base forms in various ways, for example by adding items, by concatenating two or more entities or by non-concatenative operations that somehow modify the base. Morphological operations range from more complicated concatenative ones to the subtraction of material from the base. Let's look at concatenative operations first. Yes, perhaps the simplest and most direct means by which a language can mark a category is by the addition of some material to a base form. The material that is added is referred to as affix. The operation is called affixation. Depending on their position in relation to the base, affixes are called prefixes as in remake or mislead, suffixes as in kindly, waiter or walks, infixes as in the highly expressive example kanga-bloody roue or circumfixes as in German ge-leaked. Yes, but this picture of words consisting of a string of morphs is too simple. Besides affixation, there are quite a few other formal operations by which complex word forms can be generated. These operations are referred to as non-concatenative, since the resulting word cannot easily be segmented into morphs. An important type of non-concatenative base modification changes the stem vowel as in present-day English drink, drank or in German ich trinke, ich trank. Other changes are not phonemic, but rather suprasegmental in character. In present-day English we have examples of stress shift as in contrast versus contrast. And in Russian such shift may even change the case as in nominative and genitive forms of window. Eklah, eklah. Well, and what about tonal changes as in ma in Chinese? Well, the tonal changes should also be listed under the heading of morphological operations is at least doubtful. But in any case, the change of the tone in Chinese words may distinguish different types of meaning. Ma, ma, ma, ma. In addition to the main morphological operations on bases, there are further types of morphological alternation. They range from the addition of parts of the base to the complete replacement of a form by another. Here is a technique where part or all of the affected base perhaps modified in some systematic fashion is copied. This operation is known as reduplication. Do we have any examples in present-day English? Yes, but English makes use of reduplication only very sporadically as in hickety-pickety, focus, focus and so on. But other languages make frequent use of this technique. For example, in order to make plurals or to build tenses, here's an example from Indonesia. Buku, buku, buku. And what about forms such as go, went or be, is or am? Well, they constitute the most extreme form of base modification, where one base form is replaced by another. This is most frequently encountered in the closed classes of the grammar. That is, pronouns, copula verbs and so on. So, supletion is thus a morphological operation that expresses no systematic similarity between the forms of a paradigm. Let us summarize. Okay, morphological operations define how words can be modified. That is, what type of operation is applied to change a word. Several processes, by contrast, define different ways of building words, the two principle ones being inflection and word formation. They will be discussed in another e-lecture. Until then, have a nice time. See you.