Why isn't an article put front of "whole" here?

I heard "could" is polite version of "can". Does this sentence sound not polite because of "can"?

Sometimes "could" sounds more polite than "can". However, intonation, context, and how the rest of a sentence is worded plays in big role in how "polite" it sounds. Therefore, the use of "could" or "can" is not solely what determines whether a sentence sounds polite or not. This sentence sounds neutral- it does not sound particularly polite, but it is not rude either.

What does "rattle" mean? In what circumstances could I use it?

"To rattle [someone]" is to make them nervous, worried or scared. Ex: It was hard not to get rattled when the work piled up. Ex: His confidence was rattled by the accident.

When is it appropriate to write 'a' compared to 'an'? For example, "It's an honor." and "It's a cab."

Use 'a' in front of words that have a consonant sound in the beginning. Here are a few examples: A dog, a pool, a cab, a car, a horse, a vacuum. Use 'an' in front of words that have a vowel sound in the beginning. Here are a few examples: An airplane, an octopus, an honor, an icicle. Since the word 'honor' has a vowel sounding beginning, you would need to use the word 'an' in front of it.

What does the "word cloud" mean? Could you give me some examples?

A "word cloud" is a collection or cluster of words that appear in different sizes. The bigger and bolder the word appears, the more often it's mentioned within a specific text and the more important it is. Word clouds are visual representations of information and are a very helpful form of text processing. It's a bit difficult to give an example here as they are in a visual form but you can Google it to look for image examples.

What's the difference between "being normal" and "being ordinary"?

"Ordinary" and "normal" are very similar, but they have completely different nuances. "Normal" usually has a positive connotation, and when used to describe someone, it implies that there is nothing wrong or strange about someone. "Ordinary" on the other hand often has a negative connotation. When someone is "ordinary" it usually means they are plain or simple and there is nothing special about them. Ex: She's a very ordinary girl. Ex: Everyone at the school is weird, only a few people seem normal.