Today, I am going to take you on a ride to show you the simple but difficult grammar that has embarrassed users and learners of English (both undergraduates and graduates.)
Now, fill in the gap with either of the pronouns ('I' 'Me') in the sentence below:
The Principal invited my friend and --- to his office.
Smiles. Your guess might be right or wrong. Yes, I said so because even if you got it right, you might not be able to justify your answer but if you could, kudos to you. Again, I am cocksure many people will choose 'I' as the correct answer but let's see if 'I' is actually the correct answer.
To get the answer correctly, there are certain things you should note. First, you should know that 'I' and 'Me' are personal pronouns. Whereas 'I' is a subjective case, (that is it occupies the subject position in a sentence) 'Me' is an objective case (it occupies the object position in a sentence.) For example:
I am a boy. She slapped me.
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Second, you should know that 'Me' can never take the position of 'I' in any sentence and vice versa. For example, you can't say, 'Me am a boy' neither can you say 'She slapped I.'
Finally, you should know that in any given sentence, 'I' always comes before the verb and the objective case whereas 'Me' always comes after the verb and the subjective case as shown in the sentences above.
Having known this, let's go back to our sentence of study:
The Principal invited my friend and --- to his office.
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In the above sentence, you are asked to fill in the gap with either 'I' or 'Me' and from what I have said so far, you don't need a soothsayer to tell you that 'Me' is the right pronoun to fill the gap because the verb 'invited' precedes it.
Do not be confused by the presence of 'my friend' in the sentence. If you feel 'I' is the right pronoun to fill the gap, just remove 'my friend' from the sentence and listen if it sounds correct:
'The Principal invited I to his office.'
How does it sound? Now try 'Me'
'The Principal invited Me to his office.'
How does it sound? It is grammatical now perhaps you were confused due to the presence of 'my friend' in our sentence of study.
Anytime you see a sentence like this, just look at the placement of the verb. After the verb is always 'Me' while before the verb is always 'I.' For example:
1. The principal invited my friend and me to his office.
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2. My friend and I were invited by the principal to his office.
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Sentence 1 shows 'me' coming after the verb while sentence 2 shows '1' coming before the verb thereby making both sentences grammatical
Because:
1. You can't say, 'The Principal invited my friend and I to his office' but you can say, 'The principal invited my friend and me to his office.'
2. Yov can't say, 'My friend and me were invited by the principal to his office' but you can say, 'My friend and I were invited by the principal to his office.'