A Guide to Lexical Verbs

A Guide to Lexical Verbs In English grammar, a lexical verb  is the  main verb  in a sentence. Lexical verbs- also called full verbs- convey the  semantic (or lexical) meaning  in a sentence, such as I ran fast or I ate the entire hamburger. Not surprisingly, the great majority of verbs in English are lexical verbs, which are those that are not auxiliary  (or  helping)  verbs. Lexical vs. Auxiliary Verbs Lexical verbs are the doing verbs, while auxiliary verbs are their helpers, as  eNotes  explains: Lexical verbs indicate the main action taking place in any sentence and therefore the intention of the sentence becomes clear; whereas, auxiliary verbs have a more subtle function because they often complete a sentence without the reader being aware how they contribute to [its] structure. An auxiliary verb determines the  mood,  tense,  voice,  or  aspect  of another verb in a verb phrase. Put another way, a  helping verb comes before the  main (lexical) verb in a  sentence. Together, they form a  verb phrase. In English, the auxiliary verbs are: Is, am, are, was, wereBe, being, beenHas,  have,  hadDo, does, didWill, shall, should, wouldCan, couldMay, might, must Lexical verbs constitute all the rest. Lexical verbs can be grouped according to four types:  transitive and intransitive,  linking,  dynamic  and  static (or stative),  as well as  regular  and  irregular. Transitive and Intransitive A  transitive lexical verb expresses action and needs a direct object to receive that action, notes Dictionary.com, which gives the sentence  Ã¢â‚¬Å"Alice  sees  the candle† as an example. In the sentence, sees  is the lexical verb and is transitive, while  the candle  is the direct object because it receives the action of the lexical verb sees. Intransitive verbs, by contrast,  express action but don’t affect a direct object. For example, if you say â€Å"Alice  dances,† the word  dances  is the lexical verb, but it is intransitive because it doesn’t require a direct object. Linking Verbs A linking verb is an important lexical verb  (such as a form of  be  or  seem) that joins the  subject  of a sentence to a word or phrase that  tells something about the subject. For example,  is  functions as a linking verb in the sentence The boss  is  unhappy. Note that  to be  verbs such as is can also serve as auxiliary verbs depending on how the sentence is constructed. In the sentence, Alice  is helping  Victor with his homework, is  serves as the auxiliary verb because it helps the lexical verb  helping.   Dynamic and Static A  dynamic verb- also called an action verb- is used primarily to indicate an action, process, or sensation. An example of dynamic verbs in action is this saying uttered by Hall of Fame baseball player Willie Mays in describing the game: They  throw  the ball, I  hit  it. They  hit  the ball, I  catch  it. By contrast, a static (or stative) verb  is  used primarily to describe a state or situation.  An example would be,  We  are  what we  believe  we  are.  Note that as in the linking verbs section, the  to be  verb- in this case,  are- can be a lexical verb, describing a state of being. Regular and Irregular A regular  verb is one that forms its tenses, especially the  past tense  and  past participle, by adding one in the set of generally accepted standardized suffixes. Regular verbs are conjugated by adding either -d, -ed, -ing, or -s to their  base form. An  irregular  verb, meanwhile, does not follow the usual  rules  for verb forms. In the sentence, â€Å"She  looks  in the mirror,† the main verb  looks  is a regular verb, Dictionary.com explains, adding that the past tense of look is looked. So in the past tense, the sentence would read, She looked  in the mirror. In comparison, an example of irregular verbs in a sentence would be: The bridge they  Ã¢â‚¬â€¹built brought traffic in both directions. The present tense of the first verb in the sentence is build, but in the past tense, it is  built. Similarly, the present tense of the second verb would be  bring,  but in the past tense  as used in the sentence, its  brought. Hard-Working Verbs Clearly, lexical verbs do much of the heavy lifting in English. They provide the action (intransitive and dynamic verbs), explain what is happening to various direct objects (transitive verbs), and describe states of being (static) among their many duties. Learn the lexical verbs in English and you will master the very heart of what it means to speak and write the language  correctly, effectively, and in an engaging manner

3 Types of Intermolecular Forces

3 Types of Intermolecular Forces Intermolecular forces or IMFs are physical forces between molecules. In contrast, intramolecular forces are forces between atoms within a single molecule. Intermolecular forces are weaker than intramolecular forces. The interaction between intermolecular  forces may be used to describe  how molecules interact with each other. The strength or weakness of intermolecular forces determines the state of matter of a substance (e.g., solid, liquid, gas) and some of the chemical properties (e.g., melting point, structure). There are three major types of intermolecular forces: London dispersion force, dipole-dipole interaction, and ion-dipole interaction. Key Takeaways: Intermolecular Forces Intermolecular forces act between molecules. In contrast, intramolecular forces act within molecules.Intermolecular forces are weaker than intramolecular forces.Examples of intermolecular forces include the London dispersion force, dipole-dipole interation, ion-dipole interaction, and van der Waals forces. Heres a closer look at these 3 intermolecular forces, with examples of each type. London Dispersion Force The London dispersion force is also known as LDF,  London forces, dispersion forces, instantaneous dipole forces, induced dipole forces, or the induced dipole-induced dipole force The London dispersion force is the weakest of the intermolecular forces.This is the force between two nonpolar molecules. The electrons of one molecule are attracted to the nucleus of the other molecule, while repelled by the other molecules electrons. A dipole is induced when the electron clouds of the molecules are distorted by the attractive and repulsive electrostatic forces. Example:  An example of London dispersion force is the interaction between two methyl (-CH3) groups. Example: Another example is the interaction between nitrogen gas (N2) and oxygen gas (O2) molecules. The electrons of the atoms are not only attracted to their own atomic nucleus, but also to the protons in the nucleus of the other atoms. Dipole-Dipole Interaction Dipole-dipole interaction occurs whenever two polar molecules get near each other. The positively charged portion of one molecule is attracted to the negatively charged portion of another molecule. Since many molecules are polar, this is a common intermolecular force. Example:  An example of dipole-dipole interaction is the interaction between two sulfur dioxide (SO2) molecules, where the sulfur atom of one molecule is attracted to the oxygen atoms of the other molecule. Example: H​ydrogen bonding is considered a specific example of a dipole-dipole interaction always involving hydrogen. A hydrogen atom of one molecule is attracted to an electronegative atom of another molecule, such as an oxygen atom in water. Ion-Dipole Interaction Ion-dipole interaction occurs when an ion encounters a polar molecule. In this case, the charge of the ion determines which part of the molecule attracts and which repels. A cation or positive ion would be attracted to the negative part of a molecule and repelled by the positive part. An anion or negative ion would be attracted to the positive part of a molecule and repelled by the negative part. Example:  An example of the ion-dipole interaction is the interaction between a Na ion and water (H2O) where the sodium ion and oxygen atom are attracted to each other, while the sodium and hydrogen are repelled by each other. Van der Waals Forces Van der Waals forces are the interaction between uncharged atoms or molecules. The forces are used to explain the universal attraction between bodies, the physical adsorption of gases, and the cohesion of condensed phases. The van der Waals forces include Keesom interaction, the Debye force, and the London dispersion force. So, van der Waals forces include intermolecular forces and also some intramolecular forces. Sources Ege, Seyhan (2003). Organic Chemistry: Structure and Reactivity. Houghton Mifflin College. ISBN 0618318097. pp. 30–33, 67.Majer, V. and Svoboda, V. (1985). Enthalpies of Vaporization of Organic Compounds. Blackwell Scientific Publications. Oxford. ISBN 0632015292.Margenau, H. and Kestner, N. (1969). Theory of Inter-molecular Forces. International Series of Monographs in Natural Philosophy. Pergamon Press, ISBN 1483119289.