When do I hyphenate compound nouns used as adjectives?

There isn't always a hard and fast rule surrounding each compound noun in question - some can be written several ways, for example, "bus-stop" can be written "bus stop".

However, you should ideally use a hyphen when using a compound noun as an attributive noun - in other words, using a noun as an adjective. This is to eliminate any confusion as to which words are joined.

Take your example of "English language journals". Is the word 'language' joined to English, or to journals?

• An English-language journal would be a journal in or possibly about the English language.
• An English language-journal would be a journal about language in general, that just happens to be written in English, or arguably even from England.

Your example is the former - you want to use English-language as a compound attribute noun for the journals, so the hyphen ideally should be used.

Another example would be "dry-cleaning shop", a shop that does dry-cleaning. Without the hyphen, it could be a cleaning shop that isn't wet.