Let’s take the word ‘Macrophage’ for example. Many of you will probably not understand the meaning of this scientific word. But, for the purposes of this explanation, let’s dissect the anatomy of the word. This scientific word is split into two parts – ‘Macro’ and ‘Phage’. We already know that ‘Macro’ refers to something big or large, so this in itself explains a property of ‘Phage’. In other words, whatever ‘Phage’ happens to be, we know it will be ‘large’ based on the fact it was preceded by the word ‘Macro’. As it happens, ‘Phage’ refers to ‘eating’. A Macrophage is, after all, a type of immune cell in our bodies that fights infection, and it is a large cell that eats, or digests, other dangerous organisms.

In terms of language, the ‘Macro’ part of the word is referred to as its ‘prefix’, while the term ‘Phage’ of the word is referred to as its ‘suffix’. Basically, the prefix is before a word while the suffix is placed after the word. If you learn some of the fundamental Greek and Latin prefixes and suffixes, you will be equipped with the skill of interpreting scientific words. You might not grasp the full meaning, but you may be able to grasp enough meaning to dismiss one or two potential answers. This alone is highly beneficial. The ASVAB General Science exam is replete with words such as this, and by learning this valuable skill; you are placed in a stronger position to answer ASVAB General Science questions.

The result from your ASVAB Mechanical Comprehension test, for instance, goes toward the MOS score of the following specialties:

Q. What is the name of the layer of the Earth’s atmosphere found most closely to the surface of the planet?

This is a typical example of Greek prefixes. Don’t forget – the meaning of a prefix never changes, irrespective of the word involved. Let’s assume you have no knowledge of atmospheric science and really have no idea how to solve this question. What if I were to tell you that you could “work out” the question purely on the basis of the answers involved? This is precisely what knowledge of prefixes and suffixes can do for you. In this case, the question is clearly asking us to determine the lowest layer of the Earth’s atmosphere. Given that the prefix Exo- always refers to ‘outer’, we can instantly dismiss this as a potential answer. The exosphere is, in fact, the farthest layer of the Earth’s atmosphere.

Even if that were the only Greek prefix we knew, we’ve amplified the odds of guessing the correct answer from 25% to 33%. If we possessed even more knowledge of Greek prefixes, we would learn that the prefix Meso- refers to ‘middle’. Low and behold, the Mesosphere is, in fact, the middle layer of the Earth’s atmosphere. This leaves the Thermosphere and Troposphere – meaning we’ve made the question 50:50 as a result of this deductive work. The prefix Thermo- evidently refers to ‘heat’, but Tropo- isn’t so easy. Tropo- refers to ‘change’ – so how are we to decide the correct answer between these two competing options?

Well, even if we were to make a wild guess, at least we increased the odds from 25% to 50% – this is a remarkable achievement assuming we had no prior knowledge of the layers of the Earth’s atmosphere.

Let’s take stock for a second – as we have significantly increased the odds of selecting the correct answer from 25% to 50%. This is an achievement in itself. Nonetheless, we would still like to determine the correct answer. The most logical approach would be as follows: given that ‘Thermo’ refers to ‘temperature/heat’; it’s unlikely it’s referring to the lowest layer of the atmosphere, particularly when you think how cool the planet actually is. Whereas, ‘Tropo’ refers to change and we do see significant change in this part of the atmosphere. In fact, the Troposphere is the only part of the Earth’s atmosphere that experiences weather, and it also happens to be the lowest layer of the atmosphere.

The principle behind prefixes and suffixes has probably sunk in by now, but it’s worth exploring a little bit more. At ASVAB Test Study, we positively recommend learning new scientific prefixes and suffixes for each week of your study. Let’s not forget that the meaning of these prefixes and suffixes do not change, so what you learn now will apply to every scientific word you happen to come across. One of the best ways to learn these words is to be on the lookout for prefixes or suffixes that regularly repeat. As we saw with ‘Macro’, this word repeats quite a lot in science, as will many other words. Jot them down as and when you see a pattern emerging, and store it in your arsenal for future use.

There is, of course, a tremendously diverse range of prefixes and suffixes and you should not expect to learn them all. Think of this tip as catering for the most common types, as these are the ones likely to appear on your ASVAB General Science exam. In fact, this tip is also applicable to other ASVAB tests, such as the ASVAB Mechanical Comprehension exam or, alternatively, the ASVAB Electronics Information exam. These exams also contain scientific elements, so the words you learn now will pay dividends for other ASVAB tests at the same time. Before we round this section up, we want to kick-start this process by providing you with a handful of common prefixes and suffixes.

This table provides you with ten examples of both prefixes and suffixes. You can see how the prefixes occur before the word, while suffixes are present at the end of a word. This is by no means an exhaustive list, but should go some way to improving your scientific knowledge and ability to answer ASVAB General Science questions.

Hopefully, at this stage, you’ve grasped a greater understanding of the importance of analyzing scientific words. This is just one strategy you can employ should you find yourself having difficulty while answering particular questions. If we take a look at the table above, we can see how useful these prefixes and suffixes are. Knowledge of the suffix –oma lets us know we’re talking about a tumor, or cancer. The word hydrophobic is constructed from a prefix Hydro- (meaning ‘water’) and the suffix –phobic (meaning ‘dislike of’) – so the word hydrophobic refers to a substance that dislikes water – such as oil – as oil cannot mix evenly with water at all.

There is one final exercise you should engage in. Try to think of examples of words for each of the prefixes and suffixes mentioned in the table. Let’s try one or two and see how we get on. The prefix anti-: antibiotic, antiseptic, antimatter, antisocial. What about the suffix –phobic: hydrophobic, chemophobic, emetophobia (fear of vomiting), frigophobia (fear of the cold). The purpose of the exercise is the following – it allows you to identify and recognize prefixes and the consistent meaning they have with all scientific (and, of course, non-scientific words). Through a basic analysis of common scientific vocabulary, you will grasp a greater ability at discerning its meaning and, consequently, a mechanism of score higher on the day of your ASVAB General Science exam.