Are my sentences strong enough? (do i have to change or add anything? )

I would change "Martin's and his family" to "Martin and his family's" and "his family" doesn't need to be in parentheses.

I would change the first commentary sectence to "Martin's Grandfather speaks in sioux which is his native language." and go into futher explanation on what he "knows". It's kind of a cliff hanger.

For the second commentary sentence, you should make sure to mention who's grandfather you're talking about if they are multiple in the story. Also I would change the sentence to "The grandfather exhibits his culture while wearing traditional clothing. The traditional clothing is typically worn by people of his tribe."

For the last commentary sentence, I would change it to "The quote states that the males in the family still follow traditions because it will eventually be passed down through generations.

Explanation:

these have to be in your own words

a complex sentence consists of an independent clause and one or more dependent clauses.  

to write complex sentences, we must use subordinating conjunctions.  

all the complex sentences begin with a subordinating conjunction and when it occurs, a comma must be place at the end of the dependent clause. on the contrary, if the sentence begins with an independent clause, then no comma is used.

after  

although  

as  

because  

before  

if  

since  

when  

for example,  

after she won the competition, she became very popular.  

although my father was hurt, he continued fighting for his rights.  

as all of you got a ten, you will be able to leave early today.  

before he went to the war, he asked his parents to bless him.  

if it is cold, i won’t go out.  

since you didn’t bring the homework, you will get low grades.  

when it is hot in the town, everyone goes to the beach.