词根词缀：ad-

【来源及含义】Latin: prefix; to, toward, a direction toward, addition to, near, at; and changes to: ac-, af-, ag-, al-, an-, ap-, aq-, ar-, as-, at- when ad- is combined with certain words that begin with the letters c, f, g, l, n, p, q, r, s, and t

【相关描述】The form ad- appears in this form before a vowel and before the consonants d, h, j, m, and v. It is simplified to a- before sc, sp and st.

Before c, f, g, l, n, p, q, r, s, and t; ad- is changed to ac-, af-, ag-, al-, an-, ap-, aq-, ar-, as-, and at-.

In other words, the d of ad usually changes into the same letter as the first letter of the following root or word when it is a consonant: ad-fix becomes affix, and ad-sign becomes assign; therefore, making a double consonant.

Another example includes: attract as with ad-tract (drawn towards); so it has a double t. On the other hand when ad- precedes a vowel, as with adapt, it is simply ad-apt, with one d. For the same reason, there is only one d in adore and adumbrate, because ad- has combined with orare and umbra each of which starts with a vowel.

So, remember: since these Latin words begin with vowels and not consonants, the d of ad does not double as shown in the previous examples.

【同源单词】a capite ad calcem, Ab ovo usque ad mala, Ab uno ad omnes, Abiit ad majores, abjure, accede

词根词缀：calci-, calc-, calcane-, calcio-, calco-, calcar-, calx

【来源及含义】Latin: lime, calcium; heel, bone of the tarsus; to tread [derived from calx, calcis, limestone, lime, pebble; from Greek words halix and psephos meaning "small stone, pebble"]

【同源单词】a capite ad calcem, acalculia, astragalocalcanean, calcaneal, calcanean, calcaneitis

词根词缀：capit-, capt-, cap-, cep-, ceps-, chapt-, chef, cip-

【来源及含义】Latin: head; leader, chief, or first

【相关描述】It may be surprising to see that a "captain" and a "chef" both belong to the same word family; however, a captain is, of course, the "head of a company of military soldiers", and a "chef is the captain of a group of cooks".

A chef, especially to those who love good food, is not a lowly official; and when it is remembered that the old saying that "an army travels on its stomach", a chef is every bit as important as a captain.

When the French borrowed words from Latin, they frequently used soft sounds. These French words, with their softer sounds, then made their way into the English language. At the same time, English borrowed words directly from Latin. So it is that in English we often have two words which share the same root, but which have different, though related, forms and meanings.

Don't confuse the words in this capit-, capt- unit with those in the cap-, cip-, "catch, seize" unit.

【同源单词】a capite ad calcem, achieve, achievement, achiever, acid rain, alopecia capitis totalis