base, bass, bass

Base or base means the support on which something rests--
The base of the trophy is made of wood.
Base is also a verb, meaning to use as support--
He might base his suspicions on her odd tone of voice.
Base or base also means the place or spot used as a center of activity, such as military operations--
They set up a base at the foot of the mountain.
The New York office was the base for sales operations.

Base also is an old-fashioned way of saying low, meaning a nasty person or nasty behavior--
The knight called him a base varlet and challenged him to a combat.

Bass or bass ( pronounced to rhyme with base ) means having a low tone or sound--
"Mama sang bass, Daddy sang tenor..."
The bass speaker on the stereo is making a funny noise.
He plays the bass fiddle in a combo.
Bass also means a low-pitched voice or instrument--
This part was written for a bass, not a baritone.

Bass or bass ( pronounced to rhyme with glass ) is the name of a kind of fish--
Look, there's a show on TV about bass fishing.
They went fishing and caught some trout and some bass.

Now that you know that, you can say--
The bass instruments sounded odd, so he looked in the base of the cabinet and found that the cat had used it to hide a bass he had caught in the stream."

Note--the plural ( more than one ) form of "base" is "bases"--
He hit the ball out of the park and ran the bases slowly.
Note # 2--"basis" means  a foundation, used figuratively--
Their old school days were the basis of a long friendship.
Not to be confused with the phrase "base is"--
The base is crumbling ; we will need to repair it.
The plural of "basis" is sometimes written "bases" ( pronounced base-eeze ), but many people find this affected and avoid it by using another word, like foundations, or a different sentence structure.
Note # 3--the plural of "bass" is "bass".
The plural of "bass" is also "bass", no need to remember, they are the same, singular or plural.
"Basses" would mean more than one kind or species of bass, not more than one fish.