Demonstrative Pronouns and Demonstrative Adjectives

A demonstrative pronoun represents something or someone and performs as a noun.
e.g. We are chatting about this and that.
This is Kookie speaking.
That is a good idea.

A demonstrative adjective performs as an adjective.
e.g. Those worms were big yesterday, weren't they?

The following words may be demonstrative pronouns or demonstrative adjectives.
They depend on the context of the sentence.

near in distance or time - this + these
far in distance or time - that + those

Pronouns

PRONOUNS REPLACE NOUNS - especially names of (or reference to) people 
but there are exceptions
e.g. Some are available but none are for sale yet.    - pronouns

Personal Pronouns replace proper nouns representing people - except "it"		Possessive Adjectives and Pronouns (usually connect with proper or personal pronouns)		Reflexive Pronouns
Subject in a sentence	Object in a sentence	possessive adjective	possessive pronoun
I	me	my	mine	myself
you	you	your	yours	yourself
he	him	his	his	himself
she	her	her	hers	herself
it	it	its	its	itself
we	us	our	ours	ourselves
you	you	your	yours	yourselves
they INTERROGATIVE PRONOUNS who which  what	them INTERROGATIVE PRONOUNS whom   which  what	their INTERROGATIVE ADJECTIVES whose which what	theirs	themselves

Personal and interrogative pronouns stand alone.
 Possessive and interrogative adjectives qualify another noun
- often a common noun but may be an abstract noun.
Possessive pronouns stand alone.
 Reflexive pronouns stand alone.


e.g. 1.  I warned her that her bag may be searched as it used to be mine but she was determined to face that problem herself.
2. Who is responsible for what bag?


NOTE
1. The first her in the sentence is an object of warned, so it is a personal pronoun.
The second her is a possessive adjective qualifying the noun bag.
2. who - interrogative pronoun - stands alone
what - interrogative adjective - qualifies the noun bag.



INDEFINITE PRONOUNS
someone
somebody
everyone
everybody
anyone
anybody

Prepositions

Prepositions are link words beginning phrases.
They link the trunk of the sentence with: 
the branches of time and/or place + manner + reason - adverbial phrase/s qualifying the verb
+
the descriptive branches - adjectival phrase - qualifying the noun


I read the book - main trunk of the sentence.
about dreams - adjectival phrase qualifying book. 
It begins with the preposition about. 
in the afternoon - adverbial phrase of time qualifying the verb read. 
It begins with the preposition in.
beneath the tree - adverbial phrase of place qualifying the verb read. 
It begins with the preposition beneath.



NOTE

** prepositions are usually monosyllabic - one syllable
+
** Phrases do NOT contain a verb
** A group of 3 words usually = a phrase

+
for a full list of prepositions see
English Grammar 4U Online
(exercises are included)