I decided to back up my friend's argument at the meeting.

Step 1: Analyze the question The question asks which option best explains the meaning of "I decided to back up my friend's argument at the meeting." The key is the phrasal verb "back up."

Step 2: Explain the concept A phrasal verb is a verb combined with a preposition or adverb, and its meaning is often different from the individual words. Here, "back up" means to support, confirm, or stand by someone or something.

For example:

• "The witness backed up his story." (confirmed or supported it)
• "Please back up my idea." (support it)

Step 3: Work through the options

• A. I denied my friend: "Deny" means to reject or refuse to accept. This is the opposite of supporting. ✗
• B. I endorsed my friend: "Endorse" means to give approval or support. This matches "back up." ✓
• C. I saw my friend: This only says he saw the friend, and nothing about supporting an argument. ✗
• D. I heard my friend: This only means he listened, which is not the same as supporting. ✗

Step 4: Answer Backing up someone's argument means supporting it, and the closest meaning is **"endorsed.

Step 5: Exam tip For phrasal verb questions, replace the phrasal verb with a single-word synonym and see which option fits. Some common ones:

• back up = support/endorse
• call off = cancel
• put up with = tolerate
• look into = investigate

You're doing well. Keep practising these, because JAMB English often repeats this type of question.