Learn Italian: Posso entrare?

In Italian, the subject pronoun is usually dropped because the verb itself tells you who is doing the action. The form posso specifically means "I can," so you don't need to say io posso unless you want to add emphasis.

Why is entrare in its dictionary form instead of being conjugated?

This is the rule for modal verbs like potere (to be able to/can). When you use a modal verb, you conjugate it to match the subject (like posso for "I"), and the action verb that follows it stays in its infinitive (dictionary) form.

Does potere mean "can" or "may"?

It means both! English often separates "can" (having the physical ability) and "may" (having permission). Italian uses potere for both situations. Because of this, Posso entrare? is the standard way to politely ask, "May I come in?"

How do we know this is a question without changing the word order?

In Italian, you don't need to rearrange words or add helpers like "do" to ask a question. The statement Posso entrare (I can enter) and the question Posso entrare? (Can I enter?) use the exact same word order. You just add a question mark in writing, or raise your pitch at the end of the sentence when speaking.