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：fin-

【来源及含义】Latin: end, last; limit, boundary, border

【同源单词】Ad finem fidelis, Ad finem spero, Ad finem ultimum, ad finem, ad infinitum, affinity

词根词缀：ultim-

【来源及含义】Latin: end, last, final

【同源单词】A primo ad ultimum, Ad finem ultimum, antepenult, antepenultimate, penult, penultimate

词根词缀：ultra-, ult-

【来源及含义】Latin: beyond, on the other side; excessive, to an extreme degree

【相关词根词缀】 Related "above, over, beyond the normal, excessive" word units: epi-; hyper-; super-, supra-. Inter-related cross references, directly or indirectly, involving word units meaning "more, plentiful, fullness, excessive, over flowing": copi-; exuber-; hyper-; multi-; opulen-; ple-; pleio-; plethor-; poly-; super-; total-; undu-.

【同源单词】A primo ad ultimum, Ad finem ultimum, antepenultimate, bioultrasonics, cryoultramicrotomy, exultingly