The Emphatic Form

From Akita Wiki

The emphatic form of English avoids contractions and omissions.

"I do eat." not "I eat."
"I am eating." not "I'm eating."
"I can eat." not "I c'n eat." Note: this contraction is in speech only, not writing.
"I will eat." not "I'll eat."
etc.

In most English speaking cultures (some more so than others), the emphatic is only used to emphasize clarity or indignation.

In Japanese culture however, the emphatic is used as a way to emphasize your respect for your superiors.

たべます not たべる
たべています not たべている
たべられます not たべられる
たべますでしましょう not たべるでしょう
etc.

I think the usage of the emphatic is a difference in culture not grammar.

See also