at/in the end
At the end is more neutral, it simply refers to the position of something, e.g., at the end of the week/street. In the end suggests a sense of delay, change or uncertainty.
at the end = at the point at which something ended
The hero died at the end of the film.
in the end = finally; after effort or difficulty
The hero struggled hard against cancer but died in the end.
think about/of
think about = to use your mind to imagine something or somebody
I'm thinking about my girlfriend - I wish she was here now.
think of = to have an image of something or somebody in your mind
Just think of my girlfriend - what if she was here now?
Another interesting point concerning the verb think is that it is not normally used in continuous forms when it expresses opinions but only for an action that is happening.
I don't think much of their new album. (= I don't consider it to be good.)
I'm thinking of buying their new album. (= I'm considering buying it.)
important to/for
Here, the difference lies more in the use of different structures than in a change of meaning: important to somebody versus important for somebody to do something.
Spending time with his children is important to him. (He considers it to be important.)
It is important for him to spend time with his children. (He and/or somebody else considers it to be important.)
made of/from/with
We use made of when we can easily recognize the material. When the material is changed into a completely different form, we use made from. Finally, when we mention one of several materials or ingredients, we use made with. Compare:
All my furniture is made of wood.
Paper is made from wood.
This cake is made with fresh cream.
in/on the way
In the/my, etc., way is used to express that something stops somebody from getting where they want to.
Please move on - you're in my way.
On the/my, etc., way (1) = during the journey
We saw a lot of wild animals on our way
On the/my, etc., way (2) = coming
He'll be here soon - he's on the way.
by/until six o'clock
by six o'clock = no later than at six o'clock; before six o'clock
I will finish work by six o'clock.
until six o'clock = up to six o'clock; till six o'clock (till is slightly more informal than until)
I will work until six o'clock.
day by/after day
day by day = all the time; gradually
Day by day his condition improved.
day after day = each day; repeatedly
He did the same work day after day.
care about/for
care about = to consider something to be important and worth worrying about
I do care about your opinions!
care for = to look after somebody; to take care of somebody
She moved back home to care for her sick mother.
agree with/to
agree with = to have the same opinion
I agree with you about the need for change.
agree to = to say 'yes'
She agreed to my proposal.
Note also the expression not agree with which we use when we speak about food and drinks:
Dairy products don't agree with me. (= They make me feel sick.)
speak English/in English
speak English = to be able to use English
Do you speak English?
They speak English fluently. (= They can speak English well.)
speak in English = to use English to express yourself
Would you prefer if we spoke in English?
They're speaking in English. (They are having a conversation in English.)
at that time / that time
at that time = at that period
My great-grandfather was born in 1900. At that time very few houses had electricity.
that time = on that occasion
Careful with the hammer - you nearly hit yourself that time.
these days / in those days
these days = at present, nowadays (especially when we compare the present with the past)
Kids grow up so quickly these days.
in those days = in a particular period in the past; at that time
Most women didn't go to work in those days.
during the night / all night long
during the night = in the night, either continuously or occasionally
Look at those pools - it must have rained during the night.
all night long = continuously from the beginning until the end of the night
I couldn't sleep at all - it rained heavily all night long.
See you...
