Question

...so this letter could be send to the employees.
...so this letter could be sent to the employees.

past or non past tense?

Answer 1

could be sent.....conditional past....

I wrote the letter ( past) so that the letter could be sent ( it happened in the past with the possibility of further action). We don't know whether the letter was sent or not.

Answer 2

In this case "could" is past tense of "can" or "to be able". It is used with the past participle form of the auxiliary verb "send".

See http://www.english-the-easy-way.com/English_ESL/Could_English_Verb.htm

Answer 3

also is it... "this letter will be sent to employees or to the employees to inform them about the changes"?

to employees or to the employees?

Answer 4

another question...

...we will need your help in planning it.

or
...we will need your help planning it.

Answer 5

sorry, last question.

Please let everyone know about his contributions.

-is there a better way to phrase this sentence? It sounds a bit awkard to me. Thanks.

Answer 6

will be sent... is future

Please let everyone know about ....contributions. Do they already know who the "his" is? Are you speaking about an already specified person, or are you speaking about the people to whom you are writing? That will make a difference in the effectiveness of that sentence.

Answer 7

I am speaking about an already specified person.

Answer 8

Ok. Then your sentence is alright. However, you might throw an adjective in before "contributions". That will hint at how you want this message to be conveyed. eg. his efficiency contributions... his technical contributions. etc.