छह आठ से कम है।

Hindi usually puts related elements before the main verb, and the verb often comes at the end.

So this sentence breaks down naturally as:

• छह = six
• आठ से = than eight / from eight
• कम = less
• है = is

A very literal gloss is:

• Six eight-than less is.

That sounds strange in English, but it is normal in Hindi. The comparison phrase आठ से comes before कम, and है finishes the sentence.

In this sentence, से marks the thing being compared against. It often corresponds to English than in comparisons.

So:

• आठ से कम = less than eight
• दस से बड़ा = bigger than ten
• मुझसे अच्छा = better than me / better than I am

Although से has other meanings in Hindi, here its job is specifically to show comparison.

Here, कम means less.

That is different from छोटा, which means small in size.

Compare:

• छह आठ से कम है। = Six is less than eight.
• यह घर छोटा है। = This house is small.

So कम is used for lower quantity, amount, degree, or number, not physical size.

In standard Hindi, है is the normal present-tense copula, meaning is.

So:

• छह आठ से कम है। = Six is less than eight.

If you leave out है, people may still understand you in some contexts, especially in informal speech, headings, notes, or very compressed style, but it sounds incomplete as a full standard sentence.

No. In this sentence, कम does not change for gender or number.

That is because छह is a number, and कम is being used in a fixed comparative way: less than.

So you can say:

• छह आठ से कम है।
• दो दस से कम हैं।

What changes there is the verb:

• है for singular
• हैं for plural

But कम itself stays the same.

Yes. छह and छः are two written forms for six.

In modern everyday Hindi, छह is very common and usually the simpler form learners should remember first. You may still see छः in books, formal writing, or educational material.

Both represent the same number.

Yes, this is a normal and correct way to say it.

Another very common pattern is:

• छह, आठ से कम है।

with just a pause in speech, though the meaning is the same.

In math or teaching contexts, Hindi speakers may also phrase comparisons in other ways, but X Y से कम है is the standard basic pattern for X is less than Y.

You put नहीं before the verb:

• छह आठ से कम नहीं है। = Six is not less than eight.

In Hindi, नहीं usually comes before the main verb or copula.

So the pattern is:

• X Y से कम है = X is less than Y
• X Y से कम नहीं है = X is not less than Y

Replace कम with ज़्यादा, अधिक, or in math-style language बड़ा depending on context.

Common options:

• छह आठ से ज़्यादा है। = Six is more than eight.
• छह आठ से अधिक है। = Six is greater than / more than eight.

For numbers, ज़्यादा and अधिक are usually more natural than बड़ा in everyday explanation.

So the comparison pattern stays the same:

• X Y से कम है = X is less than Y
• X Y से ज़्यादा/अधिक है = X is more than Y

Yes, if the subject is already understood from context.

For example, if you are pointing at a number or answering a question, आठ से कम है can mean:

• It is less than eight.

But if you want the full sentence Six is less than eight, then you should include छह.

So:

• छह आठ से कम है। = full sentence
• आठ से कम है। = less than eight / it is less than eight, depending on context