All this O and V and S business:
There are a variety of ways languages can make sentences. this sort of thing is usually sadly missing from syntax chapters, I'm afraid. syntax, as it is often practiced, takes a language like english as basic. English isn't basic to anything except.... well.. to more english of course. There are 6,908 other languages out there equally suited to the role as 'basic'.
All that said, languages don't vary endlessly: there are some things in human languages that are just rare.
Review for a minute your basic traditional grammar: Every sentence has to have at least a subject and a verb (don't let's quibble about commands and 'understood subjects' just for now.)
Sally dashes about.
The mighty walrus in the red hat jets off like a madman.
These are all intransitive verbs: walk, dash, jet-off. Choose a transitive verb, then add an object, and you get:
Phil reads a book.
Sally slices carrots.
The mighty walrus in the red hat leaps tall buildings with ease.
These sentences show SVO order: a subject, then a verb then an object. In Phil’s case, the subject is Phil, the verbs is ‘reads’ and the object is ‘book’. You can work out the other two, yes?
The plurality of people in the world speak a language that has this order: Mandarin, English, Spanish for example: the top couple on the list of widely-spoken languages.
However, the plurality of languages (as opposed to speakers of languages) in the world have SOV order. that looks like this:
Phil the parsley rinses.
Sally the potatoes scrubs.
The mighty walrus in the red hat the pizza orders.
Here, the verb shows up at the end of the sentence, after the subject and the object. These are languages like Japanese, turkish and Hindi.
There are a few languages, perhaps 15% of them, that put the verb first. Note that these are not questions: this is how languages like Welsh and Malagasi ordinarily make declarative sentences:
Eats Phil the sandwich.
Gobbles Sally the dessert.
Inhales the mighty walrus in the red hat the entire pie.
Note the walrus above is who is inhaling... not the thing being inhaled.
So, that's three of the possible orders: SVO, SOV and VSO. Call it 95% of the world's languages fit into one of those three groups. There are only a few languages with the the order: VOS: And, only one or two languages with the orders OSV or OVS: the latter including Klingon. For what it's worth, all o those word orders are equally easy to learn if you start from infancy. And, although OVS order is typologically rare, I did once meet a fluent Klingon speaker who told me that, once you get over the initial shock, it's not hard to deal with putting the object first. (I swear, it’s true).
Phil takes a bath.
Sally combs her hair.
The mighty walrus in the red hat polishes bottle caps.
So, we replace the subject nouns in the sentences about with he, she and it, we get:
He takes a bath.
She combs her hair.
* The mighty it in the red hat polishes bottle caps.
(Linguists use a * to tell you that a sentence is bad…. And that sentence is definitely bad!)
A pronoun replaces a whole group of words, not just a noun, bu t the whole noun phrase.
One of the essential insights from syntax is that words come in groups called phrases and those phrases group together into sentences. Language is hierarchical. Try thinking of it like this:
allophones form phonemes.
phonemes form allomorphs
allomorphs form morphemes
morphemes form words
words form phrases
phrases form sentences
Sentences form stretches of discourse.
The pronoun system of English lacks some things other languages have.
Other languages have duals (a pronoun that means two of something and not more). English used to have this.
Other languages have more distinct formality systems on the pronouns than we currently do. English used to have 'thee' as a second person informal pronoun. Yes, 'thee' was informal. Why do you think we all believe it to be formal today?
I miss, 'thee' and wish we had it back! Once, on a weekend retreat, I was called 'thee' by a group of quaker folk I was camping with: it felt good to have that sense of acceptance and togetherness that an informal pronoun can bring.
We're not without formality distinctions in our language of course and we can say, 'ya' for 'you' if we want to. Maybe 'ya' will eneventually become a whole different pronoun that we can include in our English chart.
Some languages have two kinds of first person plural pronouns: there's a 'we' that means 'you and I but not the other guy who's here'. That's exclusive we. There's a 'we' that means 'you and I and him, too'. That's inclusive 'we'. Here's what those might look like in a sentence:
(Sally, Phil and the walrus are playing pool when Sally says):
"This is dull, don't you think, Walrus? why don't we (exclusive) go out somewhere and buy some chocolate and orange juice and just really get crazy?"
Phil responds: "I seriously think we (inclusive) ought to stay put. Pool is crazy enough for a Tuesday night."
By the pronouns, you can see that Sally was inviting the walrus but not Phil. Phil was trying to get them all to stay where they were together. Poor Phil!
Note that the inclusive and exclusive pronouns need not look anything alike. One might be 'zat' and the other 'kumia'.
You know from four different things: stop and see if you can find them all.
1. First, the word 'these': it's part of the noun phrase with the noun 'girls' in it. It tells you that whatever the noun is, it's close by. If it were further away, we'd say 'those'. We also know that there's more than one of whatever it is: otherwise it'd be 'this'. (Note the * tells you that this is an incorrect sentence.)
* This two girls are very silly.
2. Next, you have the number 'two'. A pretty clear indicator that there's more than one.
3. Then, there's the inflectional suffix -s on girl-s. this is probably the first thing you noticed. without it, the sentence is bad:
* These two girl are very silly.
4. Finally, there's the verb. 'are' is a form of the verb 'to be'. the writer chose 'are' because (1) s/he wanted to be clear that the sentence is in the present tense and (2) the subject of the sentence is plural. this is wrong in standard english:
* These two girls is very silly.
These sentences are wrong, too:
* That one girl are very silly.
* That walrus laugh at the girls.
* Those two girls eats.
All of what we've been talking about here is agreement. English verbs agree with the subjects of their sentences. that is, the form of the verb changes depending on the subject. Other languages have more complex agreement. the verbs in inflected in person and number to match the subject.
Here's an example of the Spanish verb eat. Note how the ending changes for each different person and number of the subject. If you don’t do this when speaking Spanish, you sound as ungrammatical as the starred English sentences above.
tu com-es 2 eat-AGR You (singular) eat.
El com-e 3 eat-AGR He eats
And those are only the singular Spanish forms. There is a whole nother set of forms for plural subjects.
La mors-a com-e pec-es.
DEF walrus-F eat-3 fish-PL
The walrus eats fish.
La mors-a no com-e pec-es.
DEF walrus-F NEG eat-3 fish-PL
The walrus does not eat fish.
Notice that there's no word in the spanish that equates to the 'does' in the English sentence and the word order doesn’t budge.
Here’s a simplified version of how English negation works. No syntactician I know will like this account, but it does describe the facts on the surface:
1. Begin with the English sentence:
The walrus eat-s fish.
2. Adda negation:
The walrus not eat-s fish.
3. Insert a helping verb.
The walrus do not eat-s fish.
4. Move the inflectional agreement morpheme from the end of the verb and suffix it to the ‘do’ verb.
The walrus does not eat fish.
Most folks don't want to deal with anything that complex when creating a negation system. I suggest you go along with the crowd this time and make yourself a negation system more like Spanish than like english.