in
preposition
1.
(used to indicate inclusion within space, a place, or limits):
walking in the endless corridors.
2.
(used to indicate inclusion within something abstract or immaterial):
in politics; in the void.
3.
(used to indicate inclusion within or occurrence during a period or limit of time):
in ancient times; a task done in ten minutes.
4.
(used to indicate limitation or qualification, as of situation, condition, relation, manner, action, etc.):
to speak in a whisper; to be similar in appearance.
5.
(used to indicate means):
sketched in ink; spoken in words.
6.
(used to indicate motion or direction from outside to a point within) into :
Let's go in the house.
7.
(used to indicate transition from one state to another):
to break in half.