To grammar master, or to Grammar-Monster
I am currently studying the Preposition, and the following thought and question occurred on my mind,
Could a preposition word "of" be used for the following sentence?
"I was angry because of he was late again"
It is my understanding that a preposition "of" has a functionality to show relationship of a noun/pronoun to other part of a sentence. (let me know if this thinking is wrong). So usage "of" should be allowable on that sentence, right?
However, it seems like the preposition "of" is suppose to be removed, but why?
1)I was angry because of he was late again (WRONG??)
2)I was angry because he was late again (RIGHT?? )
Why is number 2 correct, but number 1 considered wrong? Please describe the reason why it is grammatically incorrect to use "of" in that sentence.
Once again, thanks in advance to whomever that responds (is the sentence structure correct?) . 
1. prepositions are followed by a noun or a pronoun, which they govern
(i) I was angry because of he was late again.
(ii) I was angry because he was late again.
(i) satisfies the rule, because the the preposition you are interested in, 'of', is followed by the pronoun 'he'.
2. pronouns governed by prepositions are in the Objective Case (nouns do not change case – they are the same whether the case is Nominative or Objective).
This is where (i) fails, since the pronoun that follows ‘of’ is not in the Objective Case: it is ‘he’ and the Objective Case is ‘him’. (More on this below).
Let’s analyse the sentence construction of (ii):
We have two ideas:
I was angry.
He was late again.
We combine these two ideas into one sentence using the conjunction ‘because’.
Looking at (i):
Instead of ‘because’, the sentence is using ‘because of’.
Now - this is actually a two-word preposition!
We have seen that the whole sentence has two ideas; and regarding the second idea:
“He was late again.”
…we see that ‘he’ is the subject of the sentence, and so HAS to be in the nominative case. So in the clause:
“…because of he was late again.”
’because of’ is a two-word preposition governing... NOTHING!
And we no longer have a conjunction joining the two clauses!
A way that we COULD use ‘because of’ is if the sentence was written:
"The boss was angry because of my/his/her repeated lateness for work.”
Here, ‘because of’ governs the noun ‘lateness’.
If I haven’t covered all your questions about this, please tell me.
Okay, thanks for responding. The grammar rule of requiring an objective case after the preposition, was an important rule that I did not know.
I do have a question and need clarification on the sentence you mentioned.
"The boss was angry because of my/his/her repeated lateness for work.”
Based on that sentence, I thought that the preposition "of" is governing "my/his/her". Why am I thinking this way? It's because "the prepositions are followed by a noun or a pronoun, which they govern" which is stated as (1) on previous post. I did not know that possessive pronoun can be used as Objective case.
The break down of parts of speach:
of = preposition that will govern "my/his/her"
my/his/her = pronoun being governed by the Preposition "of"
repeated = An Adjective? modifying the noun of "lateness" ?
lateness = noun
for = preposition that will govern the noun "work"
work = noun
Is the breakdown of part of speech correct? Thank you Grammar Monster!
Yes. Your analysis of the parts of speech is correct…
except for one.
See
possessive
and
possessive2
Read both and compare them. Then we can discuss this further. 
except for one.
See
possessive
and
possessive2
Read both and compare them. Then we can discuss this further.
Wow, i didn't even know there are separate possessive of Adjective and Personal Pronoun. Let me study this difference. Thank you Grammar Monster!!