homework

Good afternoon TOM!
Thanks for doing your homework and for sharing about your activity today.

It is really interesting to learn about cells.

I am sure that you will be able to know the different kinds of cells and where you can find it.

You did well with your homework.

Though, you need to go over the corrections and notes below.

If you have any questions, feel free to ask me tomorrow.

Teacher Nina

Needn\'t have and didn\'t need to
 
Both these forms are used to talk about past events, but there is sometimes a difference in use. When we say that someone needn\'t have done something, it means that they did it, but it was not necessary. Didn\'t need to is also sometimes used in this way:
 

You needn\'t have washed the dishes. I would\'ve put them in the dishwasher.
 
You didn\'t need to wash the dishes. I would\'ve put them in the dishwasher.
 
I didn\'t need to prepare all that food. They phoned to say they wouldn\'t be coming.
 
I needn\'t have prepared all that food. They phoned to say they wouldn\'t be coming.
 

But we also use didn\'t need to to say that something was not necessary under circumstances where it was not done:
 

The sun came out so we didn\'t need to take any rainwear on the trip.
 
We had plenty of petrol in the tank so I didn\'t need to fill up.
 
We didn\'t need to wait for long for them. They arrived just after us.

 
Needn\'t and don\'t need to
 
There is also a difference in use when these verbs are used to describe present situations. We can use both needn\'t and don\'t need to to give permission to someone not to do something in the immediate future. We can also use need as a noun here:
 

You don\'t need to water the garden this evening. It\'s going to rain tonight.
 
You needn\'t water the garden this evening. It\'s going to rain tonight.
 
There\'s no need to water the garden this evening. It\'s going to rain tonight.
 
You don\'t need to shout. It\'s a good line. I can hear you perfectly.
 
You needn\'t shout. It\'s a good line. I can hear you perfectly.
 
There\'s no need to shout. It\'s a good line. I can hear you perfectly.
 
However, when we are talking about general necessity, we normally use don\'t need to:
 
You don\'t need to pay for medical care in National Health Service hospitals.
 
You don\'t need to be rich to get into this golf club. You just need a handicap.
 

don\'t need

>> CORRECT!
need to

>> CORRECT!
don\'t need to

>> needn\'t
needn\'t have done

>> didn\'t need to do
need 

>> need to
needn\'t

>> don\'t need
don\'t deed

>> needn\'t
needn\'t

>> don\'t need
didn\'t need to bother

>> needn\'t have bothered
don\'t need

>> CORRECT!

I saw the buccal epithelial cell to use a microscope today.

>> I saw the Buccal Epithelial cell using the microscope today.

>> I used the microscope to see the Buccal Epithelial cell today.

I also use a methylene blue to dye the cell.

>> I also used a methylene blue to dye the cell.
We need to dye the cell because we can see nucleus easliy.

>> We need to dye the cell so that we can use the nucleus easily.