Useful links
Grammar
Table of irregular verbs - a list of the most frequent irregular verbs in their base form, past tense, and past participle
Tenses and time - a guide to the form and use of all tenses in English
Pronunciation
Pronunciation symbols - a list of all IPA symbols with audio pronunciation in UK and US English
Using the Cambridge Dictionary
Labels and codes - a list that explains all the different codes used in dictionary entries