Help understanding tendency tones

I’m having trouble hearing these resolutions unless it’s a resolution into the tonic

For the most part this IS what tendency tones do, they resolve to the tones of the tonic chord.

The tones involving the half steps are the real strong tendencies. TI up to DO and FA down to MI.

Those movements imply a dominant chord moving to the tonic. You can fill in the full four part harmony to see how the other voices move...

The dominant is not a tendency tone and is held. The supertonic - RE - moves down to DO the tonic.

The submediant - LA - isn't in that progression, but we can look at common progressions using subdominant chords to see the movement of LA...

Moving the voices to the closes tones of the next chord, LA moves down to SOL.

So, RE and LA sort of have a tendency to descend to tonic tones, although they aren't listed as tendency tones in my harmony textbook.

So, the tendency is the tendency to move to tones of the tonic chord. Fulfilling that move to the tonic, or at least setting up the expectation, is important. Consider a half cadence where DO moves down to TI to play the third of the dominant chord. TI has stability occurring in a cadence like that, and it really doesn't get that strong tendency quality.