Absence of the articles in set expressions
| at dinner (breakfast, etc.) at first notice at first sight at night at table at war | in search of in spite of | |||||
 by airmail
by letter
by telegram
by air
by car
by land
by plane
by sea
by ship (boat)
by train
by tram
by tube
by water
| out of date out of order out of place out of sight | |||||
| arm in arm day after day day by day hand in hand night after night night by night | ||||||
| a kind of a sort of | place, book, task, etc. | |||||
 by accident
by chance
by mistake
by name
by sight
| on account of on condition that | |||||
| to be in to go to | bed | |||||
   from beginning to end
from day to day
from east to west
from head to foot
from morning to (till) night
from side to side
in debt
in demand
in secret
in sight
in time
| to be at to go to to come to to come from to leave | school, college, (the) university | ||||
| to be at to leave to take to | hospital | |||||
| to be at to go to | sea | |||||
   in addition to
in (on) behalf of
in care of
in case of
in charge of
in reference to
| to be in to go to | church | ||||
| to be at to put to | prison | |||||
| to be in to be out of to go to | town | |||||
| to ask (for) permission to catch (lose) sight of to give offence (permission) to give way to to keep house (to do housework) to keep time | to lose touch with to lose track of to make fun of to make use of to pay attention to to set fire to to shake hands with to take care of to take notice of | |||||
In these set expressions nouns combine with prepositions or verbs and acquire a new shade of meaning, expressing an adverbial relation, a state or a process. Concrete count nouns lose their nominal meaning. Thus He isin bed may mean He is ill, or He is asleep, or He is not up. But we say: There were no chairs enough and we sat onthe bed.
My brother goesto school (college) means He learns there. However, if we mean the building or the institution, we use an article according to the general rules, as in: We shall meet atthe school. The school isn't far from our home. Ours is a verygood school. Parents are regularly invited tothe school.
The noun town without an article means the nearest big centre of population as contrasted to the country or a smaller town, it may also denote the central part of a big town, as opposed to its suburbs.
To be at sea may mean "far away from the land" or (figuratively) "to feel puzzled"; to go to sea is "to become a sailor". But we say: The swimmer jumped into the sea. We lived near the sea, etc.
No article is used as a rule when two notions, very closely related, are mentioned, as in:
They looked like mother and daughter.
We are no longer boy and girl.
It’s no use interfering into a quarrel between husband and wife.