词根：-tend-, -tent-, -tens-

【词根含义】：延伸

【词根来源】：来源于拉丁语动词tendo, tendere, tetendi, tensus or tentus(伸延),可追溯至原始印欧语ten-(伸延)。

【同源单词】：attend, attendance, attendant, contend, distend

前缀：at-

【词根来源】：ad-的变体,用在t前

【同源单词】：attach, attachment, attack, attain, attainable

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：tend-, tendo-, ten-, teno-, tenot-, tenonto-, tens-, tent-, -tend, -tension, -tent, -tense, -tensive, -tentious

【来源及含义】Greek > Latin: to move in a certain direction; to stretch, to hold out; tension; as well as tendon, sinew

【同源单词】Achilles tendon, achillotenotomy, attend, attendance, attendance, attendant