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.
The committee hasn't used time efficiently to come to a decision.
He has been studying electronic banking for more than six months.
How long has it taken the loan officer to review your letter of credit?
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))
The company hasn't had much liquidity in years.
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:
The committee hasn't used time efficiently to come to a decision.
He has been studying electronic banking for more than six months.
How long has it taken the loan officer to review your letter of credit?
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:
Hari works as an asset manager in that firm.
It's usually prudent to take this into consideration when considering which bank to select.
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:
He has been studying electronic banking for more than six months.
The board of directors and the CEO have taken a unified stance.
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.
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.
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.
I have used a debit card since the cards first became popular.
We have come to a decision since that time.
'How long' is used in questions to ask about the duration of an activity or state.
How long has the limited liability company been in existence?
How long has it taken the loan officer to review your letter of credit?