1. Singular and plural
In English, the most common way to express that there is more than one of something is the noun suffix -s:
banana – bananas
dog – dogs
Depending on the last letter of the word, the plural suffix can also be -es, -ies or -ves:
box – boxes
family – families
life – lives
There are also words that have an irregular plural. For example, a vowel might change, the word might get the ending -en, or there might be two different plurals for different meanings. These are exceptions and must be learned by heart:
tooth – teeth
child – children
penny – pennies/pence
Some words are always in the singular: money, advice, furniture
Some other words are always in the plural: looks, manners, customs
Pay special attention to words that are plural in your first language but singular in English:
homework, not homeworks
wedding, not weddings