Keywords confusion

Repeating single keywords

[Vietnamese robot]

Hi everyone,
I have a question about keyword, please help.
Lets say my site sell egg, so 'buy egg' 'chicken egg'...are a must but do I need to repeat 'egg' in every other keywords like 'duck egg', 'bird egg'...etc or just 'duck,bird' because I already put egg in previous keyword or even in title, description?

Thank you for your inputs

[mona]

Hi, Vietnamese robot. Sorry it took so long to reply. You probably don't need to repeat egg everytime. One thing you could do is read your copy out loud. Which way sounds more natural? Repeating the word or not repeating? That should give you the answer. It's important to have balance between keyword density for SEO and what your visitors will think of your copy.