Grammarly AI Prompt for Email Subject Lines

This prompt helps you write compelling email subject lines that boost open rates and drive action. Perfect for marketers, sales professionals, and anyone sending important emails. Grammarly AI will generate multiple subject line options that balance curiosity, clarity, and urgency to get your emails opened.

Works Best With: Grammarly AI | Also works with: ChatGPT, Claude, Copy.ai

The Prompt

Write compelling email subject lines for [EMAIL TYPE].

Email context:
– Recipient: [WHO I’M EMAILING]
– Email purpose: [WHAT THE EMAIL IS ABOUT]
– Desired action: [WHAT I WANT THEM TO DO]
– Relationship: [COLD OUTREACH, WARM LEAD, EXISTING CUSTOMER, etc.]
– Tone: [PROFESSIONAL, CASUAL, URGENT, FRIENDLY, etc.]

Subject line goals:
– Open rate priority: [HIGH, MEDIUM, LOW]
– Must convey: [KEY BENEFIT OR MESSAGE]
– Character limit: [IDEALLY UNDER 50 CHARACTERS]

Generate 10 subject line options using these approaches:
1. Curiosity (make them want to know more)
2. Benefit-driven (clear value proposition)
3. Urgency (time-sensitive angle)
4. Personalization (relevant to recipient)
5. Question (engage with inquiry)
6. Number/list (specific takeaway)
7. Problem/solution (address pain point)
8. Social proof (mention results or others)
9. Direct/simple (no-fluff clarity)
10. Creative/unique (stands out in inbox)

For each subject line note:
– Expected open rate (high/medium/low)
– Best use case
– Potential concerns

Avoid spam triggers like ALL CAPS, excessive punctuation!!!, or “FREE.”

When to Use This Prompt

• Your emails have low open rates and you need better subject lines
• You’re launching an email campaign and want A/B test options
• You’re stuck on how to frame your message compellingly
• You need subject lines for different audience segments

What You’ll Get

The AI will generate 10 diverse subject line options using proven frameworks like curiosity, benefit-driven, urgency, personalization, questions, numbers, problem-solution, social proof, direct clarity, and creative uniqueness. Each subject line includes expected performance rating, ideal use case scenario, and potential concerns like spam filter risk. You’ll get variety to test different psychological triggers and find what resonates with your specific audience while staying under character limits for mobile optimization.

Why This Prompt Works

• Framework diversity: Testing 10 different approaches reveals what psychological trigger works best for your audience

• Performance prediction: Expected open rate guidance helps prioritize which to test first

• Spam awareness: Avoiding trigger words prevents emails from landing in junk folders

• Character limit: Mobile displays truncate long subjects—brevity ensures full visibility

How to Customize This Prompt

1. [EMAIL TYPE] — Specific category: “sales follow-up,” “newsletter,” “webinar invite,” “product launch”
2. [WHO I’M EMAILING] — Audience: “B2B decision makers,” “newsletter subscribers,” “inactive customers”
3. [EMAIL PURPOSE] — Main content: “share case study,” “invite to demo,” “announce new feature”
4. [DESIRED ACTION] — Goal: “book a call,” “download resource,” “attend event,” “make purchase”
5. [RELATIONSHIP] — Context affects approach: cold outreach needs different style than customer emails
6. [TONE] — Brand voice: B2B enterprise is formal, DTC can be casual
7. [KEY BENEFIT] — Core value: “save 10 hours/week,” “increase conversion 25%”

Pro Tips

• A/B testing: Use the top 2-3 options to split test and see which performs best

• Emoji consideration: Add “suggest where emojis could work” for younger/casual audiences (but test carefully)

• Personalization tokens: Request “[First Name] merge field placement” for dynamic personalization

• Preview text: Include “also write preview text for each” to optimize the full inbox snippet