What a pleasure!I won the first prize. Here the underlined phrase is a/an -

What a pleasure! I won the first prize. Here the underlined phrase is an - Interjection phrase.
• Interjectional Phrase - যে শব্দসমষ্টি interjection এর কাজ করে তাকে interjectional phrase বলে।
- এটি মনের আকস্মিক ভাব প্রকাশ করে।
- যেমন -
- What a pity! He is ruined.
- What a pity! You have failed.
- Oh dear me! What shall I do now?