Past to Present
Present Perfect
Present Perfect to Express Past to Present
The present perfect connects an action or state which began in the past and to the present moment in time.
I've got a clear understanding of factors affecting our gross margin.
XYZ corporation has done better than predicted allowing for a large stock dividend this quarter.
Mr. Bill has worked in David and Stevenson Warehouse since 2007.
Positive Form:
Subject + have + past participle + (object(s))
He has submitted payment of $300 as per invoice.
Negative Form:
Subject + have + not + past participle + (object(s))
I haven't had a money market account at your bank for a long time.
Question Form:
(Wh?) + have + subject + past participle + (object(s))
How long has the limited liability company been in existence?
Present Perfect to Express Duration
When an action begins in the past and continues into the present moment we use the present perfect. This use of the present perfect expresses duration over time FROM the past moment TO the present moment.
Example:
I've got a clear understanding of factors affecting our gross margin.
XYZ corporation has done better than predicted allowing for a large stock dividend this quarter.
Mr. Bill has worked in David and Stevenson Warehouse since 2007.
Contrast to the Present Simple
The use of the present simple expresses activities that occurs on a regular basis, such as habits and routines.
Example:
The discussion centers around the bill on demand.
The futures market doesn't open for operations on federal holidays.
In contrast, the use of the present perfect expresses actions that take place over time beginning in the past and coming into the present moment in time.
Example:
I've asked my creditor to wait for more than a week, as the loan officer was supposed to come to a decision last Friday.
I've finally identified a cash cow product.
Use of 'For', 'Since' and 'How long'
Use 'for' with the present perfect or present perfect continuous to indicate the duration of an activity or state.
Our bank has used this warehouse for three years.
They have worked to our mutual benefit for four years.
Use 'since' with the present perfect or present perfect continuous to indicate a specific point in time an activity or state began.
We have come to a decision since that time.
Mr. Willis has used his debit card since getting it in November.
'How long' is used in questions to ask about the duration of an activity or state.
How long has it taken the loan officer to review your letter of credit?
How long has the limited liability company been in existence?