My dad is wearing a blue t-shirt.

Explanation:
In starting a sentence, the beginning letter of the first word
should be in big letter.
Don't forget to put the is or are after your subject. In your sentence, since
your subject is only one, or singular, you use is.
Don't forget to put the article a or an before a noun.

My mom is wearing a turtleneck shirt and black pants.

Explanation:
In starting a sentence, the beginning letter of the first word
should be in big letter.
Don't forget to put the is or are after your subject. In your sentence, since
your subject is only one, or singular, you use is.
Don't forget to put the article a or an before a noun.
There should not be a space between turtle and neck when writing
turtleneck. Also, you should put the word shirt to make the clothe more
complete.
Take note of the correct spelling of pants.
Don't forget to put a period (.) after your sentence.

I'm wearing a black t-shirt and blue pants.

Explanation:
Don't forget to put the article a or an before a noun.
Since t-shirt is a common noun, we should write the beginning letter as
small letter.
Take note of the correct spelling of pants.
Don't forget to put a period (.) after your sentence.

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Hello, Jenny! Thank you for passing your homework! I like what your mom is wearing! She's wearing a turtleneck shirt! You did good in making those sentences. You just weren't able to put is and a. Don't worry, we'll practice more on it. Kindly review the corrections above. Have a great weekend, Jenny!

~ T. Mary