Using todo, toda, todos and todas to say all, every and the whole (indefinite adjectives)

Todo is a Adjetivo indefinido meaning all, every or the whole. It expresses an undefined quantity and is usually followed by a definite article or a possessive adjective.

Look at this table:

Now let's see how to use this adjective!

1. Todo + [definite article/possesive adjective] + [masculine singular noun]

2. Toda + [definite article/possesive adjective] + [feminine singular noun]

3. Todos + [definite article/possesive adjective] + [masculine plural noun]

4. Todas + [definite article/possesive adjective] + [feminine plural noun]

Be careful! There are some time phrases where using todo/toda or todos/as changes the meaning:

Sometimes, we can find todo/toda directly in front of a common noun with no article. This is to add emphasis to the noun. For example:

Extra note about countries and cities

If we want to say "the whole of a country/city" we don't generally use the definite article, although there are some countries that often keep the article, for example:

Deciding whether you need to use todo or toda in front of a country is tricky; how do we know the gender of a country? 

There is a general rule for countries. If the name of a country ends with a NON-stressed -a, we use "toda":

If it ends in any other letter or a stressed -a, then we use "todo":

For cities, this rule seems to be more flexible, so it is acceptable to use the masculine or the feminine form:

One reason why we may also use the feminine form is because we are talking about "la ciudad de..." and ciudad is a feminine noun so makes us think of the city as a feminine noun. 

See also Using todo to say everything or all (of it) (indefinite pronoun).