The tone level entirely decides the meaning of the word.

Example:
The following two words have directly adverse meaning depending on tone.
When you write the two words they look the same in english bu quite different in thai.
Click on the speaker symbol to hear the pronunciation:

glay means “near”

glay means “far away”

It can often be easier for beginners to memorize phrases rather than words since phrases forms little “melodies”.

I translate the thai expressions as literal as possible. In this way, you can understand each word's meaning and later reuse them in other contexts.
Sometimes the order of words will therefore be a bit strange in english, but I think you will understand.