#1. Jane's sister is a nurse.
Is is a present tense be-verb, so we must agree with the present tense be-verb is.
#2. I've been to Germany.
I’ve been to Germany = I have been to Germany.
For past participle (have been), we agree with have.
#3. I have two brothers and two sisters.
Have is a present tense general verb, so we must agree with present tense general verb do.
#4. I'm hungry.
I‘m hungry = I am hungry.
Am is a present tense be-verb, so we agree with the present tense be-verb am.
#5. Bob and Susan have been married for a long time.
For past participle (have been), we agree with have.
#6. I went to bed late last night.
Went to bed is a past tense general verb, so we must agree with did.
#7. I want to go shopping now.
Want is a present tense general verb, so we must agree with the present tense general verb do.
#8. Don't buy any rice. We have some.
Buy is a general verb, so we must agree with do.
#9. We were so happy to hear the news!
Were is a past tense be-verb, so we must agree with the past tense be-verb were.
#10. I'll be late tomorrow.
Will changes the be-verb to future tense, so we must agree with will.