one by one; each; every; at intervals of
process; course; mechanism
to be added to; to be appended; to join in (e.g. a group of friends); to participate; to increase (e.g. heat); to gain in (e.g. influence)
to take lessons in; to be taught; to learn (from a teacher); to study (under a teacher); to get training in
(something) has never occurred; to have never done (something); such a thing has not happened; never happens; there is never a time when
(starting) from nothing; from scratch
your (visual) observation
to keep a watchful eye on
to go uninvited; to call on without an invitation; to barge in on; to throng to; to crowd into; to converge upon
study; diligence; discount; reduction
constraint; reserve; feeling hesitant; being afraid of troubling someone
to be needed; to be wanted
to summon courage; to be brave
indifferent; half-hearted; dispirited; listless
to go by; to go past; to run (between; of a rail service, bus route, etc.); to operate (between); to go indoors; to go into a room; to penetrate
insufficiency; deficiency; shortage; dissatisfaction; discontent; complaint
change; variation; variety; diversity; inflection; declension
puzzling; tangled; complicated; complex
indicates supposition; if ... then; when; (typically after someone's name) indicates exasperation
half in doubt; half-convinced; dubious; incredulous
bag; satchel; briefcase; basket
exercises; practice problem
to indicate; to show; to point to
writing; composition; essay; sentence
to be placed on; to be set on; to be piled on; to appear (in print); to be mentioned; to be recorded
practical use; application; conjugation; inflection
to examine; to look up; to investigate; to check up; to sense; to study
to fill in (field, entry, etc.); to fill out (form); to post a message (e.g. on a bulletin-board); to store; to write (data); to flash
imperative sentence; imperative statement
the future (usually distant); future tense; the world to come
to make time; to carve out some time (to do something)