95
APPENDIX. FUNCTIONS AND NOTIONS
Definitions
Most definitions contain at least the following components: (a) the name
of the item being defined, (b) is / are, (c) a generic (or type) noun (e.g.
instrument, tool, device) and (d) a statement of the main function, use or
purpose of the item:
A motion sensor (a) is (b) a device (c) for detecting human or animal
movement (d).
More complex definitions can also contain one or more of the following
optional elements: (e) appearance, (f) property, (g) type, (h) components, (i)
material, (j) material, (k) application:
A thermostat (a) is (b) a sensing (g) device (c), consisting of a sensing
element and a transducer (h), which controls sources of heating and cooling to
maintain a desired temperature (d) and is found in many home and industrial
heating systems (k).
Describing properties
You can describe the properties of materials in a variety of ways.
•
present simple active:
This material resists heat. The material bends
easily.
•
can/ can't:
You can stretch it. It can be stretched. The material can be
bent easily.
•
without + -ing form:
The material can absorb a blow without bending (=
... but it doesn’t 't bend).
•
resist/ resistant/ resistance:
This material resists water very well. It is
highly water resistant. It is an extremely water-resistant material. It has
good resistance to water. It has excellent water resistance.
•
able/ ability/ unable:
This material is able/ unable to resist heat. It has the
ability to resist heat.
•
capable/ capability/ capacity/ incapable:
This plastic is capable/ incapable
of resisting chemicals. This plastic has the capability to resist / of
resisting chemicals. This steel has the capacity to resist bending.
•
suffixes -able/ -ible/ -proof.
flammable, fusible, waterproof.
Use or function
The use or function or purpose of a device or object can be described in
various ways:
•
present simple:
The carburetor mixes air and petrol.
This indicates the
action of the device itself (without human agency) and is often used in
