's

1. verb /z/

are

The dog’s running after me!

2. pronoun /z/

a) <span class="use-with-mention">Contracted form of <span class="mention">us</span> found in the formula <span class="mention">let’s</span> used to form first-person plural imperatives. <span class="mention">Let’s</span> is now considered as a compound.</span>

What are you guys waiting for? Let’s go!

b) <span class="use-with-mention">Contracted form of <span class="mention">as</span> in its nonstandard use as a relative pronoun.</span>

All’s he wanted was to go home.