Active voice and passive voice

I very confused about active voice and passive voice, Following these sentense Plaese explain me why frist sentense is passive voice and second sentense is active voice

1. The Contractor shall be responsible for the design, supply and test the
automatic flow control system for remote manual and automatic
control of the penstocks.

2.The Contractor shall design and implement temporary flow diversion
to ensure that screw pump installation at the Stage IV Inlet Works is
carried out in a safe and dry working condition.

Hello,mooyong

I will try to help.
Listen my friend.

The first sentence "The Contractor shall be responsible for the design.."
is not passive voice.It's just a simple sentence with a modal.

how did I know that these sentence is not passive voice ?

1- "shall " ,similar to "will", is a modal . And it ,often with the pronouns' I' and 'we',is used to indicate future action.

2- the modals in passive voice follow this structure :
subjet+modal+be verb (in the appropriate tense)+past participle

In your sentence we have subjet(the contractor)+modal(shall)+be+But here we need past participle of the verb and " responsible" is not a past participle ,it 's not even a verb.

* This is an example for a modal in the passive voice :
All library books must(should/may/might/..) be returned to the library
before July 1st.

For the second sentence "The Contractor shall design and implement..).It's also a sipmle sentence to indicate a future action.Why ? becasu of the using of the modal "shall".
If you want to use passive voice, the sentence should be :
A flow diversion shall be designed and implemented by the constractore to ensure..

I hope that I was helpful...

Remember I could be easily wrong, so that you should wait for the other members to reply on you..I'm just a beginner trying to help as mutch as I can
Take care ........

----- I am not an ESL teacher -----

I completely agree with abdoss.

Yes, neither of your sentences is in the passive voice.

Yes. I'm also agree with abdos.
As for Passive Voice, we usually talk about the object instead of the subject as in active voice.
For example:

I painted the wall. (Active Voice)
The wall has been painted by me. (Passive Voice)

Notice that "wall" in Active Voice is Object.

Quote:

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Originally Posted by apiz

I painted the wall. (Active Voice)
The wall has been painted by me. (Passive Voice)

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If the second sentence is a passive version of the first, then shouldn't the tense be the same (was painted)? ;-)