Word Formation: Prefixes

You will study how to create new words using prefixes.


Word Formation: Prefixes

The Milky Way Galaxy

Instructions: Read the text. Look at the letters in bold.

The Milky Way is the Galaxy that contains our Solar System. The Milky Way is visible from Earth as a hazy band of white light, some 30° wide, across the night sky. The light originates from the accumulation of unresolved stars and other material located in the direction of the galactic plane. Dark regions within the band, such as the Great Rift and the Coalsack,are areas where interstellar dust blocks light from distant stars. The area of sky that the Milky Way obscures is called the Zone of Avoidance.

The Milky Way has a relatively low Surface brightness. This makes the Milky Way difficult to see from brightly lit urban or suburban areas, but very prominent when viewed from rural areas when the Moon is below the horizon.

Center of the Milky Way viewed from the Mountains of West Virginia, USA, Forest Wander (2010) Wikimedia Commons.

Retrieved and adapted, january 2019 from: https://en.wikipedia.org/wiki/Milky_Way

Getting started: Stars and planets

Instructions: Read the text. Then, do the activity suggested.

The Milky Way contains between 200 and 400 billion stars and at least 100 billion planets. The Milky Way may also contain perhaps ten billion white dwarfs, a billion neutron stars, and a hundred million black holes. Filling the space between the stars is a disk of gas and dust called the interstellar medium. The disk of stars in the Milky Way does not have a Sharp Edge beyond which there are no stars. Rather, for reasons that are unexplained, the concentration of stars decreases with distance from the center of the galaxy.

The milky way contains at least one planet per star, resulting in 100-400 billion planets according to a January 2013 study. A different analysis of five-planet star system Kepler-32 estimated that at least 17 billion Earth sized exoplanets reside in the Galaxy.

Retrieved and adapted, january 2019 from: https://en.wikipedia.org/wiki/Milky_Way

The Milky Way Galaxy

Instructions: Drag the word that completes correctly the sentence.

ExoplanetsBlack HolesInterstellarUnexplained

1. For ___________ reasons, the concentration of stars decreases with distance from the center of the Milky Way.

2. There are at least 17 billion ___________ in the Galaxy.

3. The ___________ medium is a disk of gas and dust situated between the stars.

4. The Milky Way contains stars, planets, white dwarfs, and ___________.

Let’s study about Word Formation using prefixes

Instructions: Read about Word formation:

Word Formation We can create new words using “prefixes”. Prefixes are letters which we can add at the beginning of a word to create a new one with a different meaning. Prefixes can, for example, create a new word opposite in meaning to the word the prefix is atached to. They can also make a word negative or express relations of time, place or manner.

Some of the most common prefixes are included in the next table:

Anti-against / opposed toanti- government
Il-, im-, in-, ir-notillegal, impossible,insecure,irregular
Over-too muchovercook
Sub-under, belowsubmarine
Un-remove, reverse, notundo, unhappy

Retrieved and adapted, january 2019 from: https://dictionary.cambridge.org/es/gramatica/gramatica-britanica/word-formation/prefixes".



Instructions: Drag and drop the correct prefix


___ communism,

___ pack,

___ national,

___ ordinary,

___ biography,

___ existence,


The Milky Way visibility

Instructions: Choose the right option in the following sentences.

  1. The substellar/ interstellar medium is the matter and radiation that exists in the space between the star systems in a Galaxy.
  2. The reasons that explained the decreasing number of stars far from the center of the Galaxy are well-known/ unknown.
  3. The band of white light from Milky Way is viewed easier in ultradark / non-dark environments.
  4. The light pollution in the cities makes impossible/ compossible o distinguished the Milky Way by naked eye.
  5. That pollution is caused by the overuse/ misuse , of artificial light in urban places.
done Check


Instructions: Add the correct word to fill in the gaps.


The Milky Way’s spiral structure is ___________,and there is currently no consensus on the nature of its spiral arms. Galaxies commonly have arms that branch, merge, twist ___________, and feature a degree of ___________. In December 2013, astronomers found that the distribution of young stars and star-forming regions matches the four-arm description of the Milky Way. Thus, the Galaxy appears to have two spiral arms as traced by ___________ stars and four spiral arms as traced by gas and young stars. The explanation for this apparent discrepancy is ___________.