Acknowledges that Hamlet himself has said something refreshingly honest.

“Try it” as in both “attempt this plan” and “put this to the test” (as above).

Polonius proposes to “loose” Ophelia (as if he has her in captivity) when Hamlet’s around, then observe the two of them behind an arras (tapestry).

Arras can also have a theatrical meaning:

a curtain suspended loosely across a stage and used as a backdrop or part of a stage setting.

Polonius’s arras trick doesn’t work so well the second time around (in 3.4).

“Falconry” tapestry, possibly from Arras, 1430s. Victoria and Albert Museum.

To “loose” is also a barnyard expression. A farmer would “loose” a cow, in heat, to a bull.

Polonius’s use of the word in its farmyard sense seems to be sustained with the “farm and carters” of the next line. However, given his penchant for circumlocution, it is possible that “loose” here evinces his insensitivity to what he is proposing.

Another sign of Hamlet’s melancholy and preoccupied mind–he has a habit of pacing the lobby of the castle for hours.

If this is part of his “antic disposition” act, it takes some commitment (four hours!).

Possible symptom of what’s now classified as Acute Stress Disorder?

Hyperarousal or anxiety, including sleep problems, irritability, inability to concentrate, an unusually intense startle response, hypervigilance, and physical restlessness (pacing the floor, fidgeting, etc.).

I’d fain know: I’d like to know.

Polonius asks, in effect, Have I ever steered you wrong? The king replies (warily?): Not that I know of.

https://www.youtube.com/watch?v=mU8RSGbRthI

Of course this moment is filled with dramatic irony: Polonius has no idea that Hamlet might be faking lovesickness, let alone why.

Ever the politician, Claudius chooses to mollify Polonius.

Watch Patrick Stewart play this moment (substituting “friend” for “man”) in the 2009 David Tennant Hamlet:

https://youtu.be/3vTXtdQ63FA?t=5m41s

tokens: tokens of affection.

See 1.3:

POLONIUS
…This is for all:
I would not, in plain terms, from this time forth,
Have you so slander any moment leisure,
As to give words or talk with the Lord Hamlet.

Tony Church (Polonius) with Glenda Jackson (Ophelia), 1965 Royal Shakespeare Company production of Hamlet. (Tony Church/Denver Post)

The dying Hamlet agrees to exchange forgiveness with Laertes. “Free of it”: free of the guilt of Hamlet’s death.

There may be an implication here that Hamlet and Laertes do not die “with all [their] imperfections on their head,” as Hamlet’s father did. They make a kind of reckoning, however informal, with their earthly sins.

Polonius brags of having sensed the love between Hamlet and Ophelia before Ophelia confessed it. We’ve seen in 1.3 that he did indeed have his suspicions.

Yet another injunction to hear, pay attention, understand. These recur throughout the play, from the Ghost’s speech to Polonius’s chatter to Hamlet’s last plea to Horatio to tell the “audience” of onlookers what has happened.