FOR, SINCE, AGO, HOW LONG …?, HOW LONG AGO …?

I. FOR

A) Use:

For expresses a duration that is to say a length of time during which the action took place.

B) Exemplification:

- I have been waiting for him for two hours or I have been waiting on him for two hours

- She has worked on the project for days

- He has already sent the mail to the supplier

C) The tenses we use 'For' with:

For is used both with the present perfect tenses and the past perfect tenses.

- She had travelled to the Middle East for one month prior to getting married

- She had been driving a hatchback for a few weeks when a Sports Utility Vehicle hit her

D) Other uses of 'For':

1. For: in a past action

Can be used to express that something happened in the past and is no longer in effect at the time of speaking. For is therefore used with a time word.

I worked there for three years back in the nineties

It rained for two days without letting up!

He taught in high schools for thirty years before retiring

2. For: conjunction or linking word

Can also be used as a conjunction or linking word.

I paid a visit to her as a realtor for I wanted to buy a semi-detached house (for = because)

I'm here for I would like to get a piece of advice from you (for = because)

3. For: purpose

Can be used to talk about a purpose or a reason for something.

- I wear a tie and a suit for a job interview

- She called me on the phone for a quick overview on the day's schedule

4. For: someone

Can be used to introduce the person or people receiving something. 

- I have a gift for Mother's Day

- I did it for you

- There's a message for you at the reception desk

5. For: exchange

Can be used to refer to an exchange.

- It costs 10€ for 1 item

- I'll grant you a discount for large quantities

6. For: because

Can be used to refer to a reason given in support of an action.

- I'm learning hard at the moment for I want to get my diploma

- I'm here for I would like to get a piece of advice from you

7. For: multi-word verbs or adjectives

. To look for (I'm looking for a job after landing a degree in Sales Management)

. To care for (I care for my staff to provide them with equal opportunities)

. To ask for (She asked for a day off following the celebration of the music festival of which she is an active member)

. To be responsible for (She is responsible for the Purchasing department at headquarters)

II. SINCE

A) Use:

Since expresses the starting point of an action. What matters here is the start of the action from the moment something actually happened.

B) Exemplification:

- I haven't seen her since she graduated from college

- I have been sweating since this morning due to the high daytime temperatures

- They have been running the small and medium sized company since last year

C) The tenses we use 'Since' with:

Since is used both with the present perfect tenses and the past perfect tenses.

- She has left for the Middle East since Monday to attend the signing of a business contract

- She had been driving a hatchback since she came of age when an SUV (Sports Utility Vehicle) hit her

D) Other uses of 'Since':

Since: as a result, consequently

- Since you didn't pay me, I won't post the invoice

- I'm going to treat myself to a nice set of clothes since I have a job interview to go through

- Since you failed your exam, you will have to work harder

Since: with ever

You can also add 'ever' before since which means continuously, since that time

- I accompanied him to the station and we have stayed in touch ever since

- Ever since he was fired from his job, I haven't heard from him

III. AGO

A) Use:

Ago expresses an action that took place in the past and is completely finished at the time of speaking. What matters here is to recount a past action. The past is in the past and cannot be resurrected in the present but simply recalled.

B) Exemplification:

- I saw her 10 years ago and haven't heard from her since

- I visited my closest relatives last month

C) The tense we use 'Ago' with:

Ago is exclusively used with the simple past tense

- I signed up for English lessons a year ago

- I received the results of my job interview a few days ago

- They responded to my request about a week ago

IV. HOW LONG …?

A) Use:

How long asks a question that automatically calls for an answer using the present perfect tenses and the past perfect tenses. It comes down to: how much longer and until when.

B) Exemplification:

- How long have you known her (for)? I have known her for almost a year

- How long has she been talking on the phone? She has been talking on the phone for twenty minutes

- How long have they been operating this machine? They have been operating this machine since this morning

C) The tenses we use 'How long' with:

How long is used with the present perfect tenses and the past perfect tenses.

- How long have you worked on the project? I have worked on the project for a few years now

- How long have you been working for your current company? I have been working for my current company for two years

D) How long is also used with other tenses:

Can be used with the present, the past or the future. Discover the following examples: 

- How long did you stay in Paris? I stayed in Paris for ten days or I stayed ten days in Paris

- How long does he need to stay in bed to heal? He has to stay in bed for about five days to heal

- How long are you staying in Paris? I will stay in Paris for two weeks 

- How long will you be on a business trip? I will be on a business trip all week starting Monday

V. HOW LONG AGO …?

A) Use:

How long ago asks what period of time is required in a completely finished period of time. This is similar to Since when …? 

B Exemplification:

- How long ago did you travel abroad? I travelled abroad three years ago

- How long ago did you phone her? I phoned her a few minutes ago

- How long ago did you speak English to a foreigner? We spoke English to a foreigner last month

C The tenses we use 'How long ago' with:

How long ago is used with the past only as it refers to something that took place in the past and is now completely finished

- How long ago did you work on the project? I worked on the project a few years ago

- How long ago did you hear this news? I heard this news a while ago

- How long ago did you learn English irregular verbs? I learnt/learned English irregular verbs seven years ago