Verb nominalization with plain form vs の

Question

I was wondering if there is any clear rule as when to use plain form vs の

eg. その食べっている人。 ラメンをたべるのが好き。

Answer 1

They are grammatically different. ご飯を食べている人 is "person who is having a meal". This phrase ご飯を食べている modifies 人.

Nominalization with の is used for nominalizing a phrase or sentence. This phrase ラーメンをたべる is nominalized by using の such as ラーメンをたべるの.

For example, ラーメンを食べる人が好き(I like the person who eats ramen), ラーメンを食べるのが好き(I like eating ramen).