1
I almost forgot my keys.
To sign this, you would use the sign for 'almost' followed by 'forgot' (wiping your fingers across your forehead and pulling into an 'A' handshape) and 'keys' (twisting your dominant index finger in your non-dominant palm).
2
We are almost there.
You can use 'almost' to show you are close to a destination. Sign 'we' by moving your index finger from one shoulder to the other, sign 'almost,' and then point to the location or use the sign for 'arrive.'
3
I'm almost finished with my homework.
Sign 'my,' then 'homework' (touching your cheek with a flat 'O' hand, then signing 'work'), followed by 'almost,' and finally 'finish' (flicking both hands outward to show completion).