amortization and depreciation

[msyourtaxservice]

where in the form 4562 can I enter an amortization for a year previous to 2019 of an intangible asset?

Also I would like to know if I can deduct 50% instead of 100% of an new asset in 2019?

[Terry53029]

Prior year amortization line 43 part Vl. Bonus deprecation is 100% or regular MACR for assets put in service 2019. 50% not allowed

[sjrcpa]

 If eligible for Section 179, you can elect this for one-half the cost.