Marital = relating to marriage or the relations between a married couple.

• She wanted to talk about their marital problems.
• Marital bliss is the share and care the couple give between them.
• Strict marital fidelity is essential for a happy married life.
• Extra-marital relations may spoil the joyful atmosphere in the family.

Martial = relating to fighting , war, army.

• Freedom of press was curtailed to a great extent during martial regime.
• Martial law.
• A court martial stripped him of his military rank.
• The recruits drilled while singing martial songs.
• Polonius sent his son to Paris for learning martial arts.