Keith Kelly looks at examples of the language of hypothesis, prediction and conditions from the area of science, covering common structures and lexical phrases.

## Predicting with a greater degree of certainty

… will happen / Many people predict that … will happen
What would you predict as the effect of mixing together all three colours?

If … happens, … will (certainty)
If a woman is infected while pregnant, it will not affect the unborn child during pregnancy.

As … happens, (then) … will happen
As it gets colder, the rate of transpiration will slow down.

When … happens, (then) … will happen
When the immune system breaks down, the patient will then suffer many infections and diseases.

Because … happens, (then) … will happen
Because the plants are crowded together they will compete for light and become weak and not grow well.

## Predicting with a lesser degree of certainty

If / Since … happens, … may / might / can / could happen (possibility)

• If there is a chance of problems during labour that might damage mother or baby, the doctor may decide to deliver the baby by doing a Caesarean section.
• Suggest what might happen if the thermostat in an iron broke so the contacts were always closed.
• If the diver descends too quickly, there can be damage to his or her ears, lungs and eyes.
• Since male and female reproductive structures are separate, it is possible that pollen from one flower could pollinate the stigma of the same flower or of a different flower.

If … happened, … would happen (probability)

• If an elephant could double its size, its legs would probably break.
• What would happen to flowering plants if all the flowers in world were picked and used for decoration?

Assuming … happened, … would happen (probability)
Calculate the effort needed to push the sack up the plank, assuming that there is no friction.

If … had happened, … would have happened (speculation about the past)
If a giant asteroid had not wiped out dinosaurs on the planet, would in all likelihood have continued to roam the planet to this day.

## Predict using a negative construction

Unless … happens, … will not happen / … will not happen, unless … happens
A leaf does not produce starch unless it is exposed to sunlight.

If / When … does not happen, … will happen / … will not happen, if … does not happen

• If the fan is running, the rate of evaporation from the paper is increased and so the water will not climb so far upwards before reaching the equilibrium point.
• When a plant does not receive sunlight through its leaves, it will die.

### Common lexical phrases

Whether or not … happens, depends on … / … happening requires (entails, calls for, demands, needs) …

• The size of the image in a convex mirror depends on the distance the object is from the mirror.
• What are the conditions needed for rusting?
• Streamlined objects reduce the energy required to move forward.
• Whether or not the strings on a tennis racket move during a stroke depends, in part, on the friction between the strings.

A condition (requirement / prerequisite / necessity) for … to happen is … / One of the conditions for … is …

• Heat, fuel and oxygen are the conditions required for fire, and a fire is extinguished if any one of these conditions is removed.
• A condition for a point being located on a curve is that its coordinates have to verify the given equation of the curve.

For … to happen, … is essential (necessary / crucial / vital)

• Soil also contains air and water, which are essential for the living organisms in the soil.
• Protein is necessary for the development of the muscles in the growing foetus.
• Gravity reaches out even into space, and is vital in keeping satellites in orbit.