Commend = compliment, congratulate ; praise formally or honour officially.

• We should commend her for her commitment and compassion towards the under-privileged and down-trodden.
• Securing the first rank is a commendable achievement in his academic pursuits.
• The fishermen from Thiruvanathapuram received letters of commendation from the authorities for their brave and selfless services rendered during the floods in Kerala.

Comment = remark, observation ,opinion, criticism etc.

• The auditor signed his Report with some comments on the overall performance of the company.
• The DEO commented that the teachers should devote a little more time for self-study in order to make teaching more effective.
• The inspectors commented on the quality of the food served in primary schools at the cost of the public exchequer.