英语的apple和德语的apfel是同源词(或同根词).

English apple and German apfel are cognate words.

一些法律使用域词语和其同源词构成训释.

Some words should combine with their cognate words to get the meanings.

很必然地，这些原本的同源词看上去就并不相像了。

Such cognate words don't necessarily mean the same.

根据这些提示就不难推断出它们是同源词并有着相似意思。

So, with these clues in mind, we can reasonably conclude that these words are cognates, or words of common origin and similar meaning.

其研究同源词的方法众多，并非只有“一声之转”；

There are many methods of the study of paronyms besides change of pronunciations .

本文对其中部分同源词进行考证阐释，以验证它们的可靠性。

This paper does textual research about partial paronym in order to verify the authenticity of etymological relation.

本文对其中部分同源词进行考证阐释,以验证它们的可靠性.

This paper does textual research about partial paronym order to verify the authenticity of etymological relation.

它们可能是被误解的同源词或者只是外来语，而不是源于同根。

They could be false cognates or just directly borrowed terms rather than derived from a common root.

所有这些二词一组的同源词说明了，北京话的基本词汇层并非只有一层。（最后一句搞不清啦，意译了，呵呵。

All these etymological doublets indicate that the Peking dialect is comprised of a basic native word stock overlaid with one or more strata of extraneous material.