I'm afraid I'm rather tied up at the moment.

Meaning

I'm too busy to help right now.

Examples

• John: '<b>I'm afraid I'm rather tied up at the moment.</b> Perhaps tomorrow?'
• Alice: 'Could you possibly help me with the presentation?'<br>
• John: 'Would you be available to proofread my essay?'<br>
• Alice: '<b>I'm afraid I'm rather tied up at the moment.</b> I have a pressing deadline.'