Learn English – When to use “I” or “I am”

adverbsgrammarsentence-constructionverbs

I've been having some texting with someone else. None of us are English native speakers, but we are both pretty advanced. She thinks I'm more advanced than her, although I think I just have more experience; but about knowledge and language dominion, we are pretty similar.

I have some doubts, because in a moment she wrote:
"I'm really envy how good you know English, but I pretty sure that it's all the result of hard work".

I know the right way of this sentence is:
"I really envy how good you are in English, but I'm pretty sure it's all the result of hard work".

"How good you know English" sounds right to me. My doubts are about:

  • "I'm really envy" -> "I really envy" and
  • "I pretty sure" -> "I'm pretty sure".

By intuition, I'm sure the versions at the right side are the correct ones, but I don't know how to explain it, and I haven't found anything about the differences between using "I [verb]" and "I am [adjective / adverb]".

In fact, I've found that "I'm" is used before a verb, to be descriptive and to announce your location:
"I am walking to the store", "I am a doctor", "I am at the store". But also, it's used before an adjective or adverb in simple present:
"I am sure", "I am hungry".

In contrast, "I" is used in simple past, future and simple present, often followed by "to be":
"I have to go to the store", "I cook hamburgers", "I envy your skills".

I've been searching everywhere the right uses of "I" and "I am", and I haven't fount anything regarding this doubts.

Why is my suggestion right, or if it's right at all? Are both versions right?

Best Answer

Given I am X, what's valid for X is in almost all cases is the following:

  • an adjective (I am hot, I am third, I am ready)

  • a noun or pronoun (I am a cat, I am a worker, I am him, I am George)

  • a verb's present participle form, these always end in -ing (I am walking ..., I am envying ...)

  • a verb's past participle form if it makes sense to express a state and can also work as an adjective (I am destroyed, I am surprised)

  • rarely, a preposition (I am of the tribe, I am to lead my group)

  • any of the above with an adverb in front, (e.g. I am very X)

Adverbs can appear between I and am, like really, definitely, etc.

What X can't never be is the plain form of a verb.

So you can say I am walking but never I am walk.

You can say I am to walk but not I am walk.

You can say I am cooking hamburgers or I cook hamburgers but never I am cook hamburgers.

You also are required to express am in all the above situations. Am is not optional, but it's often said in the contracted form I'm.