The preposition without means ‘not having something’ or ‘lacking something’:

I can’t drink tea without milk.

I found myself in a strange country, without money and with no one to turn to.

When without is followed by a singular countable noun, we use a/an:

Don’t go out without a hat. It’s very cold.

Not: Don’t go without hat.

Without + -ing form can also mean ‘if someone does not do something’:

I couldn’t get the picture out of the frame without breaking the glass. (if I did not break the glass)

We don’t omit the indefinite article a/an after without + singular countable noun:

How can you live without a telephone nowadays?

Not: … without telephone …

We don’t use without to mean ‘apart from’ or ‘in addition to’:

Apart from my mother tongue, I can speak two other languages.

Not: Without my mother-tongue …

Without has a negative meaning. We don’t use another negative word immediately after it:

The flight was delayed and we had to wait for five hours without anything to eat or drink.

Not: … without nothing to eat or drink.