sol, We have diminutive suffixes in English. However, many of the diminutives have become common words and are no longer recognized as diminutives. Many of the suffixes are borrowed from foreign languages, so a full list of them would be rather large. Usage is common, but informal. There are no strict rules, i.e, there is no way to predict which ending (if any) can be attached to a particular noun, and usage can vary from region to region. -a short list of diminutive endings- -ck: bullock, hillock, paddock -ey/-ie/-y: dearie, doggy, kitty, movie, Mikey, Bobby, Suzy -ette: diskette, cigarette, kitchenette, suffragette -let: piglet, chicklet, applet, eyelet, gauntlet, tablet -ling: duckling, gosling, foundling, darling -kin: catkin, babykin, munchkin, napkin Prefixes mini: minibus, miniskirt, minisub, etc. micro: microprocessor, microskirt, microscope, etc. We don't have augmentative suffixes, but there are some prefixes. mega: megaphone, megalith over: overseer, overlord, overdrive super: superman, superdog, superintendent grand: grandparent, grandmaster Again, many of the diminutives and augmentatives have become lexalized, i.e, they have become common words that are part of the vocabulary.

In English, augmentative forms are created by prefixes, such as super-, over-, mega, or grand-. See http://en.wikipedia.org/wiki/Augmentative The diminutive hardly exists in English except in isolated forms, like piglet for pig. The suffixes -ie or -y are sometimes added to names to form a diminutive, like Johnny for John.

We don't have them in English.

I don't think there are any general diminutive and augmentative rules in English. In Portuguese almost any noun can be made small or large by adding the appropriate suffix. English has no equal. That said, there are some word ending for the diminutive form of a word. You've already indicated one, adding the letter y to the end of a word such as kitty, for little cat. There is also doggy and horsy as diminutive terms for dog and horse. However, the rule does not extend well. The word girly would not mean little girl, but someone behaving as a girl. There is also the suffix 'ette' that is used to make some words diminutive. Examples include cigarette, kitchenette, lunchonette (small restaurant that only serves lunch). But this ending is not used very often. I can't think of any English form to augment a word.