And

You can imply the word "and" by repeating a particle or preposition.

jan li kama li tawa.
jan li kama li tawa.

People come and go.

sina pali e lipu e toki sin.
sina pali e lipu e toki sin.

You make books and new languages.

In subjects

To connect multiple subjects, use the particle en.

soweli en waso li pona.
soweli en waso li pona.

Mammals and birds are good.

It might help to imagine a hidden en at the start of every sentence. This way, you repeat en like the other particles; you just always drop the first en.

In modifiers

Saying "and" between modifiers would be the same thing as listing them.

sike loje suli
sike loje suli

big (and) red ball

Repeating dropped li

There is some disagreement over whether to repeat li when the first instance is dropped after mi or sina, or to make a new sentence. Multiple sentences might make a clearer distinction between statements like these:

mi ike li wile weka.
mi ike li wile weka.

Those of us who are bad need to go away. (Can also mean:)

mi ike. mi wile weka.
mi ike. mi wile weka.

We are bad and we need to go away.