Possible Duplicate:
“More clear” vs “Clearer”, when to use “more” instead of “-er”
What's the comparative for the word modern?
Possible Duplicate:
“More clear” vs “Clearer”, when to use “more” instead of “-er”
What's the comparative for the word modern?
More modern.
"Moderner" is entirely non-standard. If you want to avoid "more", you could use a synonym like "fresher" instead. Of course, it's not a full synonym, but it may serve your purpose.