Can't help but ~; unbearably ~; so ~ one can't stand it

Can't help but ~; unbearably ~ (strong visceral or emotional impulse)

Can't help feeling ~; inevitably feel ~ (emotion welling up from within)

Can't help doing ~; cannot resist ~; cannot keep oneself from ~

Never cease to ~; earnestly and enduringly ~ (of prayers, wishes, respect)

Extremely ~; nothing could be more ~; the height of ~ (expression of extreme emotion)

Indescribably ~; beyond words; there's no describing how ~

How ~ (it is)!; What a ~!

I want (someone) to ~; I wish (someone) would ~

Truly ~; how ~ (a thing) is (heartfelt observation about a general truth)

Used to ~ (nostalgic recollection of a past habit)

How ~ (it must be / was)!; how very ~!

How ~ it is! (exclamation expressing the speaker's emotional reaction)

To one's ~; ~ly enough; what's ~ is that ~

There is something ~ about it; it has a certain ~ quality

(To think) that ~!; the very idea of ~! (surprise, admiration, contempt, or disbelief)

How I wish (to) ~; I really hope ~ (heartfelt desire)

Isn't there some way to ~?; can't we somehow ~? (strong wish often phrased as a question)

To think that ~!; the very idea of ~!; I never imagined ~

Should; ought to (moral/social obligation based on the speaker's judgment)

Should be; is expected to; it is supposed that (logical conclusion from known facts)

It is certain that ~; surely ~; bound to ~ (speaker's absolute conviction)

Have no choice but to ~; there is nothing to do but ~; can only ~

Should; ought to (general moral norm or social common sense)

Nothing other than ~; precisely ~; exactly ~ (strong identity assertion)

Merely ~; nothing more than ~; only ~ (downplaying or limiting)

That's what ~ is; that's the very definition of ~; it is precisely the case that ~ (speaker's conclusive judgment)

Will not ~; probably will not ~; must not ~ (negative volition or negative conjecture)

Just have to ~; that's all there is to it; there's nothing more to it than ~ (limiting resolve or minimizing)

Is worthy of ~; deserves ~; is worth ~ (evaluation of merit)

Cannot but say ~; have no choice but to conclude ~ (reluctant but unavoidable assertion)

Must not ~; shall not ~ (strong prohibition, archaic/formal)

Extremely ~; utterly ~; the height of ~ (often negative evaluation)

The height of ~; the pinnacle of ~; the ultimate in ~ (extreme degree, literary)

Let's ~ (polite volitional / invitation)

Won't you ~?; Shall we ~? (polite invitation)

Must not ~; may not ~ (prohibition)

Must ~; have to ~ (obligation / necessity)

Don't have to ~; it's not necessary to ~ (lack of obligation)

Please ~ (polite request)

Please don't ~ (polite negative request)

Do ~ (firm command, often parent to child or teacher to student)

Had better ~; should ~ (strong advice / recommendation)

How about ~?; Why don't you ~? (gentle suggestion)

May ~; it's okay to ~ (permission)

Make sure to ~; try to ~; make an effort to ~ (conscious habit formation)

Must ~; do ~ / don't ~ (written rule or instruction)

There's no need to ~; you don't have to ~; it's not that ~ (emphatic non-necessity)

Should; ought to (moral/social obligation based on speaker's judgment)

Should; ought to / should not; ought not to (general moral norm or social common sense)

Have no choice but to ~; can only ~; there's nothing to do but ~

Cannot afford not to ~; it would be unacceptable not to ~ (double-negative obligation from social expectation)

Cannot but ~; have no choice but to ~; compelled to ~ (reluctant but unavoidable action)

Shall we not ~?; Let us ~! (formal, rhetorical call to action)

Should ~; it's important to ~ (personal advice framed as universal wisdom)

Nothing beats ~; ~ is the best; best to ~ (strong subjective recommendation)

Will not ~; shall not ~; probably not ~ (negative volition or negative conjecture)

Must not ~; should not ~; that cannot be ~ed (attributive prohibition, formal/literary)

It would be strange not to ~; it is only natural that ~; one naturally ought to ~

Cannot avoid ~ing; must ~; won't get away without ~ing (social/moral compulsion)

Be forced to ~; be compelled to ~ (by external circumstances beyond one's control)