本文整理了英语前缀com-及其变形co-、cor-、col-的含义，表示共同、和、完全的意思。

1. 概述

前缀com-及其变体con-,cor-,col-表示共同, 和, 完全。举例如下：

comment(评论), compile(编辑), correlation(相互关系), collect(收集), corruption(贪污腐败), collaborate(合作, 合著)

2. 前缀com-以及变体

2.1 com-，在b,p,m之前

a prefix meaning “with,” “together,” “in association,” and (with intensive force) “completely,” occurring in loanwords from Latin (commit): used in the formation of compound words before b, p, m: combine; compare; commingle.

2.2 con-, 在除b, h, l, p, r外的辅音

variant of com- before a consonant (except b, h, l, p, r) and, by assimilation, before n: convene; condone; connection.

2.3 co-, 在元音，h, gn之前

variant of com- before a vowel, h, and gn: coadjutor; cohabit; cognate. The prefix co-, now productively forms new words from bases beginning with any sound ( co-conspirator; co-manage; coseismic), sometimes with the derived sense “auxiliary, subsidiary” ( coenzyme; copilot), and, in mathematics and astronomy, with the sense “complement” ( codeclination).

together; joint or jointly; mutual or mutually. coproduction
indicating partnership or equality. cofounder, copilot
to the same or a similar degree. coextend
(in mathematics and astronomy) of the complement of an angle. cosecant, codeclination

2.4 col-, 在l之前

variant of com- before l: collateral.

注：前缀col-还是colo-的变体(在无音前)，如colostomy.

2.5 cor-, 在r之前

variant of com- before r: correlate.

参考资料：
[1]百科词条：前缀
[2]http://dictionary.reference.com/