If you think about it for a minute, you will realize that astronomer is different from walker, a person who walks. You can't say: one who astronomes. So astronomer is a word that you might have to look up to get the right meaning.
You know many other -ical words, like economical and alphabetical, so why should you look up astronomical? Because it has that special second definition, which might be the one you need: "almost too large to imagine." You could figure out definition 1 for yourself, but you might not know about definition 2. It is a good idea to look up new words made with suffixes unless you are very sure that the simple and obvious meaning is what you need.
Morphemes that are added ahead of roots are called prefixes. The pre- in their name is a good example. It means before in time or order, and you have seen it used in many other words: prepare, predict, precede, prepay.
You already know a great number of prefixes and use them all the time. One of the most familiar is un-, which means not or the opposite of. It can be added to hundreds of words; some are unkind, uncomfortable, unusual, and uneasy. Just about as common is re-, meaning over again or back again, as in renew, to make new over again, or repay, to pay back again.
Do you recognize post-, which means after or coming after, in postscript, something written after the rest of a letter? Anti-, opposed to or against, as in antiaircraft? Sub-, under, as in submarine?
If you know all the parts of a word, usually you have a good idea of what the word as a whole means. For example, re- plus pay plus -ment equals repayment. And un- plus alter plus -able equals unalterable.
Sometimes, though, one of the word parts can fool you. Here is one that you know, but can you see how someone might be tricked by it?
un-armed adj. 1 Not armed; without arms or weapons, especially a gun. 2 Without sharp prickles or points, as the spines, plates, etc., of some animals or plants.
In unarmed, the arm part means weapon, not a part of the body. This makes an important difference in the meaning of the word.
Learn all you can about prefixes and suffixes and other word parts. They are very handy to know. But remember too that you will often have to look up entries for words that have very common word parts in order to be absolutely sure of their correct meanings.
Mix-ups and Confusions
Unfortunately, our language sometimes makes it hard for us to keep some words sorted out from some other words either because they look so much alike or because they sound so hungarian private teacher district 19 much alike. Your dictionary has several ways of helping you with these problems.
When you were learning to find entries in your dictionary, you discovered words that might seem to be difficult to find because two (and sometimes more) completely different words are spelled exactly the same. These are called gergely homographs, and there are a good many of them.
Just turning over the pages of entries beginning with F, for example, you would find thirty-four of this particular kind of word. You could make a list beginning with fair1 and fair2. It would include fell, which has four numbered entries, fine, which has three, forte, two, and fry, two. Other letters of the alphabet would show you many more.
Many times, these homographs are pronounced alike as well as spelled alike, but not always. If you discover homographs that are new to you, don't look just at the meaning. Check the pronunciations too, and learn them. Otherwise, you will sound as though you are using the wrong word even though you know the correct definition.
Here are some familiar homographs that are pronounced differently. Do you recognize them?
minute1 wind1 sewer1 wound1
minute2 wind2 sewer2 wound2BACK