In-class assignment 2     corrections	

Internet is an important invention.	article	
Mobile phone is very convenience.	singular / plural     pos	
Although car is useful, however, it cause pollution.	linkers  singular / plural     	
We can use internet to connect to other.	pronoun   article    w/w	
Computers become important in our life.	tense   number agreement	
People may learn more knowledge from internet.	modal    collocation  article	
We no need to go out. We may do banking transaction on internet.	pronoun   verb form  modal singular / plural     article	

After hard working five years he was a manager.	word order   preposition  w/w	
He have many knowledge of accounting.	collocation      quantifier 	
He need to livelihood the family.	w/w   tense    	
She wanted to earn much money.	quantifier	
At last she was successed in her business.	pos	
He always say we work hard and no give up.	reported speech	
I very appreciate my boss for his hard working.	w/w    pos	
I first knew Joanne ten years ago.	w/w	
She was very hard to study.	adjective / adverb	

Answers	

The Internet is an important invention.

Mobile phones are very convenient.

Although cars are useful, they cause pollution.

You can use the Internet to connect to other people.

Computers have become important in our lives.

People can learn a lot from the Internet.

You don't have to go out. You can do your banking on the Internet.

After working hard for five years he became a manager.

He knows a lot about accounting./ He has a good knowledge of accounting (formal)

He had to support his family.

She wanted to earn a lot of money.

At last she was successful in her business. / ..she succeeded in her business.

He always says we should work hard and never give up.

I admire my boss very much for his hard work.

I first met Joanne ten years ago.

She studied very hard. / It was very hard for her to study. 
(* These two sentences have completely different meanings.)