Is the sign for 'matter' the same as 'important'?
Yes! In ASL, the concepts of 'matter' (as in significance) and 'important' use the exact same sign. The context of your sentence and your facial expressions will help clarify your exact meaning.
Can I use this sign for physical matter in science?
No, this sign is strictly for the concept of importance or significance. If you are talking about physical matter in a scientific context (like solids, liquids, and gases), you would typically fingerspell M-A-T-T-E-R.
How do I sign 'it doesn't matter'?
As a beginner, you can simply sign 'NOT' followed by 'MATTER'. While there are specific, more advanced ASL idioms for 'doesn't matter' or 'don't care', signing 'NOT MATTER' is perfectly clear and widely understood.