With a question tag:

We have to do another experiment today, ____?

antecedent

pseudo-passive

Using inversion:

You should not leave your child unsupervised at any time.

Using extraposition:

That the supermarket will be closed this weekend is a nuisance.

What’s the difference between extraposition and discontinuity?

Adding a suitable tag:

There is little ink in the bottle.

Using transferred negation:

I remember that I have never seen such a man.

Using a relative clause:

My special gratitude goes to Professor Smith. Without his help the thesis would have been impossible.

Using subordination:

The International Club meets only once every semester for this special event. The first thing on our agenda is to have the secretary read the minutes of the last meeting.

Using coordination:

Short periods of fasting could help people lose weight. Short periods of fasting could lead to better health.