Phonology, syntax, and semantics are three important areas of study in linguistics. Phonology is all about the sounds of a language. Remember the lyrics of that old song, “You say to-mā-to; I say to-mah-to”? A phonologist is interested in how and why the two vowel sounds differ among various groups of people.

Let's look at another example. In Old English (spoken in England from about the mid-fifth century through the eleventh century), words that look much the same as those of modern English were actually pronounced quite differently. The Old English word “wē” means the same as the modern “we,” but it was pronounced like “way” rather than “wee.”

Phonologists study sounds like these, how each language combines them to form words, and how they change over time. Books of phonology, or sections of language books that deal with phonology, often list the vowels and consonants of a language, explain how they are pronounced in various situations, and sometimes explore how they developed over time.

Syntax is the study of how words are combined into phrases and sentences and how they function in a phrase or sentence. For instance, each language has rules about the proper order of words and phrases. English is quite strict in most cases, for it typically forms sentences with a subject-verb-object order like this: Mary bought groceries. We would think it quite odd if someone said, “Groceries Mary bought” (although we might think that the speaker wants to place some special emphasis on groceries), and no one would remark that “Groceries bought Mary”!

Other languages, however, allow for a more flexible syntax. Latin, for example, relies less upon word order and more upon endings that show a word's function in a sentence. In Latin we can say, “Marcus videt urbem” (Mark sees a city) or “Urbem Marcus videt” or even “Urbem videt Marcus,” and the meaning remains the same, for “urbem” is always the direct object form of the noun “urbs” no matter where it is located in the sentence, and Marcus is always the subject form.

While phonology focuses on sounds and syntax on structures, semantics concentrates on meanings. Scholars who study semantics look closely at the meanings of words, how languages use those words literally and figuratively, and how meanings change over time. What do we think of when we hear the word “doom”? Something negative, right? The idea of someone going to his doom is certainly not a pleasant one.

In Old English, however, the word “dōm” could mean “doom” in a modern sense but could also refer to a judgment either positive or negative or even the glory that results from a positive judgment. The word's meaning was much broader. Semantics explores those meanings, the changes in their range over the centuries, and the reasons behind the changes.

Semantics also studies how language is used figuratively. Think of all the different meanings a person can attach to the word “fine.” Literally, it means that something is good or acceptable, but figuratively, people can use it to mean the exact opposite. Imagine you are upset with a friend and yell, “Fine!” as you are walking out of the room and slamming the door behind you. You certainly don't mean that all is well; you just mean you want to end the argument for now. Semantics identifies and examines these kinds of non-literal (in this case, ironic) meanings.

In linguistics, phonology is the science of sounds; it shows us how sounds are organized and combined into words, and it explains what those sounds are and why they are relevant. Phonetics is a study which focuses on the physical properties of those sounds, specifically the physical properties of speech; it tells us how people produce speech sounds and how they recognize and perceive them.

In phonology and linguistics, these units of sounds are called phonemes and they show us how words differ from one another, both in pronunciation and meaning. When we say "the phonology of English," for instance, we mean the sound system or sound structure of the English language.

For example, consider the pronunciation of the words "chalks" and "boards." In this case, your vocal cords will vibrate when you pronounce the word "boards," but they will not vibrate when you say the word "chalks." In other words, the last phoneme (s) in both words will either be voiced or voiceless, depending on the sounds which come before it.

Syntax explains how words and other linguistic elements are organized and arranged in order to form sentences. For example, look at the following sentences:

She stared at her child lovingly.

She lovingly stared at her child.

Lovingly, she stated at her child.

The different arrangement of just one word (lovingly) created three different forms of syntax. It’s important to know that the order of words must be grammatically correct and abide by all linguistic rules of a given language.

Semantics is the study of the connection and correlation between words, phrases or texts; it analyzes and explains their meaning and shows how people understand and interpret that meaning. For instance, the word "turn" has several interpretations and meanings.

Phonology is the study of how sounds are used in languages. In particular, phonology is used to show how patterns of sounds are used to build a language. It is very closely related to phonetics, but the main difference is that we use phonetics to analyze how all human sounds are made, while phonology only analyzes patterns of sounds in individual languages. An example of a phoneme is the sound /d/ in dew vs. the sound /r/ in rue.  The difference in these two sounds tell us that dew and rue are different words.

While Phonology looks at individual sounds, syntax analyzes the way that words are strung together in a language to form parts, like phrases and clauses, and then even sentences. A language's syntax is divided into two parts. First, syntax looks at individual parts of speech, such as nouns, verbs, and adjectives. Second, syntax looks at the functions of words within the sentence, such as the function of a noun as a subject and object.  For example, in the sentence, "The cat sat on the mat," both cat and mat are nouns.  However, the English language makes the first noun in a sentence the subject.  So we know that cat is the subject of the sentence; the subject that is doing the doing; while, mat is the object that is sat upon.

Finally, while syntax shows us how we string words together to make meaning, the study of semantics analyzes how users derive meaning from language, especially with respect to language change, which is the development of language over time. An example of semantics would be how one impacts a listener by saying "Y'all gots me some chocolates?" vs. "Do you have any chocolate you can share with me?"

Phonology is the study of words, especially spoken words.  It is the formal term denoting all examinations of the communication media of speech and writing.  Example: “The development of regional accents is a subject for phonology, not sociology.”  Syntax is simply the Greek word for “order,” and in fact can be used to discuss the order of any process – for example, the order in which a mechanic tunes a motor, the “syntax” of the steps  – what steps come first, what next, etc.  Example in language:  “In English, the rules of syntax call for an adjective to precede the noun it modifies (big, black dog); in French, the syntactical rules call for the adjective to follow the noun (Vin Rose, red wine).  Another example:  “Questions have a reverse syntax from statements – the predicate comes before the subject.”  Semantics is the study of subtexts, connotations rather than denotations, the subtle weight that word choice gives to discourse.  Example: “The rebels destroyed law and order” vs. “The Freedom Fighters ousted the corrupt Establishment.”  Semantics are apparent in advertisements:  “Treat your family to a greasy, fat-laden, unhealthy dinner” would not be a good Macdonald’s ad.