What's the different point between "prefer" and "rather"?
And are there different ways that how to use them other than I wrote the example sentences?......

I'm using them (I like A than B for NOW or THIS MOMENT.)
"I'd rather swimming than playing tennis TOMORROW."
"I'd rather he was more complain me freely no pamper."

(For example, I love A than B no limited.)
"I prefer wild flowers than roses."
"I prefer live country side than a big city."

Yoroshiku onegai shimasu.

Question

What's the different point between "prefer" and "rather"?
And are there different ways that how to use them other than I wrote the example sentences?......

I'm using them (I like A than B for NOW or THIS MOMENT.)
"I'd rather swimming than playing tennis TOMORROW."
"I'd rather he was more complain me freely no pamper."

(For example, I love A than B no limited.)
"I prefer wild flowers than roses."
"I prefer live country side than a big city."

Yoroshiku onegai shimasu.

Answer

The correct construction is:

"I'd prefer TO DO this or that"
or
"I'd rather DO this or that"
but
"I prefer THIS THING to that thing"

So:
"I'd rather swim than play tennis."
"I'd rather he complain and not pamper me."
"I prefer wildflowers to roses." (you can't use "rather" here.)
"I prefer to live in the countryside rather than a big city."

Answer

Prefer is a verb. Rather is an adverb.

"I'd rather swim than play tennis tomorrow."
"I'd prefer that he complained to me freely, without any pampering."

"I prefer wild flowers to roses."
"I prefer to live in the countryside than in a big city."