Other Activities on Your Turn

1. You can communicate however you are able, through brief utterances and gestures, as you take your turn. (91)

2. You can also interact with one object or feature of the environment for free, during either your move or your action. (91) Here are a few examples:

draw or sheathe a sword
open or close a door
withdraw a potion from your backpack
pick up a dropped axe
hand an item to another character

Go here for other examples.

Dropping an item does not count as an interaction with one object. See here.

Retrieving an item from a bag of holding requires an action. (210)

Drinking or administering a potion takes an action. (68)

Interacting with a second object requires the Use an Object action. (91, 94)

Some magic items and other special objects require an action to use. (206)

If an activity needs special care or presents an unusual obstacle, an action may be required.

A Strength check may be necessary to force open a stuck door. (79)