并 + 不 / 没 (emphatic denial)

"Actually, no — not at all"

• variant of 并并bìng before not不bù / not / haven't没méi firmly denies an assumption: "it's not actually …".
• this这zhèvariant of 并并bìng不难bù nán = "this isn't hard at all (despite what you think)."
• variant of 并并bìng says "contrary to expectation".

Subj + variant of 并并bìng + not不bù / not / haven't没méi + Verb / Adj

• variant of 并并bìng strengthens the negative, pushing back on a belief.

this这zhèactually并bìngnot不bùhard难nán。

• this这zhèvariant of 并并bìng不难bù nán = "this really isn't hard."

Counters an assumption

• Use variant of 并并bìngnot不bù / variant of 并并bìngnot / haven't没méi when correcting what someone wrongly assumes.

Recap

Read the full reference: HSK 4 grammar — Sentence patterns.