UTTERANCES, SENTENCES, AND PROPOSITIONS
An UTTERANCE is the USE by a particular speaker, on a particular occasion, of a piece of language, such as a sequence of sentences, or a single phrase, or even a single word.
Ex.: “Hello”,
        “Not much”
        “talaamidzu”
       “ooh..”
         “Pxgotmgt”
         “Schplotzenpflaaaargh”
A  SENTENCE is a string of words put together by the grammatical rules of a language expressing a complete thought. A given sentences always consists of the same words, and in the same order.
a. Hellen rolled up the carpet
b. Hellen rolled the carpet up
c. Sincerity may frighten the boy
d. Sincerity may frighten the boy
A sentence is a grammatically complete string of words expressing a complete thought.
Ex.: I would like a cup of coffee   S
Coffee, please NS
In the kitchen NS
Please, put it in the kitchen S
Which of the following utterances are tokens of whole sentences (S) and which are not(NS)
‘John’ S/NS
‘Who is there’ S/NS
‘Mine’ S/NS
‘It’s mine’ S/NS
‘Where shall I...?’ S/NS
Utterances of non-sentences, e.g short phrases, or single words, are used by people in communication all the time.
Given below are some sample conversations. In each case the second utterance is not a token of a sentence. Write out a full sentence expressing the intended meaning more fully.


(1) Magnus: “When did Goethe die?”
     Fred: “In 1832” Goethe died in 1832............................
(2)Hostess: “Would you like tea or coffee?”
     Guest: “Coffee, please”  I like  coffee..........................
(3) A: “Who won the battle of Waterloo?”
     B: “Wellinton”  Wellinton won the battle of Waterloo. .................................
A Proposition is that part of the meaning of the utterance of a declarative sentence which describes some state of affairs. this typically involves persons or things referred to by expressions in the sentence. In uttering a declarative sentence a speaker typically asserts a proposition.
The notion of truth can be used to decide whether two sentences express different propositions.
Consider the following pairs of sentences. In each case, say whether there are any circumstances of which one member of the pair could be true and the other false.
(1) Harry took out the garbage
     Harry took the garbage out Yes/ No
(2) John gave Mary a book
      Mary was given a book by John Yes / No
(3) Isobel loves Tony
      Tony loves Isobel Yes / No
(4) George danced with Ethel
      George didn’t dance with Ethel              Yes / No                              

(5) Dr. Findlay killed Janet
      Dr. Findlay caused Janet to die                 Yes / No                                  






(1) Fill in the chart below with ‘+’ or ‘-‘ as appropriate. Thus, for example, if it makes sense to think of a proposition being in a particular regional accent, put a ‘+’ in the appropriate box; if not put a ‘-‘.
utterances sentences propositions
Can be loud or quiet + - -
Can be grammatical or not + + -
Can be true or false + + +
In a particular regional accent + _ -
In particular language + + -
(2) can the same proposition be expressed by different sentences?                                                                           Yes / No
(3) Can the same sentence be realized by different       utterances(i.e. have different utterances as tokens)?  Yes/No    
(4) draw a family tree relationship between these notions.  





A  SENTENCE is a string of words put together by the grammatical rules of a language expressing a complete thought. A given sentences always consists of the same words, and in the same order.
 An UTTERANCE is the USE by a particular speaker, on a particular occasion, of a piece of language, such as a sequence of sentences, or a single phrase, or even a single word.
 A Proposition is that part of the meaning of the utterance of a declarative sentence which describes some state of affairs. The state of affairs typically involves persons or things referred to by expressions in the sentence. In uttering a declarative sentence a speaker typically asserts a proposition.
               
 Logical properties of sentences
Logical relations between sentences
Relations that logicians recognize between propositions.
There are five relations will be recognized here: implication/entailment, equivalent/paraphase, contrariety, contradiction and independence.
1. Entailment
Entailment is the relation which holds between p and the corresponding Q items in the following:
P Q
It’s a dog it’s an animal
John killed the wasp the wasp died
All dogs are purple my dog is purple
 Properties of entailment:
• The sentences are being used in a particular context with particular reference
• The relation is not determined by context: it is context independent, since it depend entirely on the meanings of the constituents of the sentences.
• The truth of the entailed sentence must follow inescapably from the truth of the entailing sentence
2. equivalent/paraphase
propositional equivalence between two sentences can be defined as mutual entailment. That is two sentences always express the same proposition. The examples are:
John killed the wasp the wasp was killed by John
The wasp is dead the wasp is not alive
It began at 10 o’clock it commenced at 10 o’clock
(if it is true that John killed the wasp, then it is also true that the wasp was killed by John and if it is true that  the wasp was killed by John, then it is also necessarily true that John killed the wasp)
3. Contrariety
The relation in terms of entailment, by saying that S1 and S2 are contraries if S1 entails not-S2, but not-S2 doesn’t entail S1 (and vice verse). The following are examples:
John killed the wasp The wasp is alive
John killed the wasp Mary killed the wasp
This paint is red The paint is green
4. Contradiction
Contradictory propositions must have opposite truth values in every circumstance. In any particular circumstance, one member of a contradictory pair must be true and the other false. By saying that S1 and S2 are contradictories if S1 entails not-S2, and not-S2 entails S1(and vice verse). The examples are:
The wasp is dead The wasp is alive
John is still singing John is no longer singing
No dogs are brown At least some dogs are brown
(if The wasp is dead, then it is false that it is alive: if it is false that the wasp is dead, then it must be the case that is alive, and if it is false that it is alive, then it is dead)
5. Independence.
The truth values vary independently of one another: they may be both true, both false, or one true and the other false:
John is retired. Mary is married.
It is Tuesday today. Independence day falls on a                                    Wednesday this year.
Analytical, paradoxical, and synthetic sentences
• Analyticity
Analytic sentences are sentences which automatically express true proposition in any context. Here are the examples:
Bachelors are unmarried.
John’s uncle is a man.
This proposition is either true or false.
• Paradox
Paradoxical sentences automatically express false propositions:
Bachelors are married.
John’s sister is a man.
This red paint is green.
• Syntheticity
Synthetic sentences are those which express true propositions in some contexts and false ones in others(this is the normal kind of sentence used in communication):
John’s sister is married.
This paint is green.
All dogs are brown.

Paraphrase
Entailment
Contradiction: negative entailment