If a friend with type o+ blood needs a blood transfusion, can type A+ blood be given safely to him?

Blood types that match A person who has: Can receive:
A- blood
A-, O- blood

A+ blood
A-, A+, O-, O+ blood

B- blood
B-, O- blood

B+ blood
B-, B+, O-, O+ blood

AB- blood
AB-, O- blood

AB+ blood
AB-, AB+, A-, A+, B-, B+, O-, O+ blood

O- blood
O- blood

O+ blood
O-, O+ blood

That is a negative. Only o- o+

blood type must match the recipient's exactly: Blood type O negative is the only type of blood that people of all other blood types can receive. This is helpful in emergency situations when the patient needs a transfusion but their blood type is unknown. Because of this, O negative donors are called "universal donors." People who have type AB blood are called "universal recipients" because they can safely receive any type of blood.

No. Giving Type A blood to a person with Type O is likely to be fatal, and will in any case provoke a serious reaction.

Type O blood can be given to anyone.
Type A blood can be given to people with Type A or AB.
Type B can be given to people with type B or AB.
Type AB can be given to people with Type AB.

Rh - blood can be given to people with either Rh.
Rh + can only be given to people who are Rh+.

No. Type O negative blood can be donated to anyone, but only type O may be given to a person with type O blood.

No. The only types he can have are O negative and O positive.