Which of the following sentences does illustrate subject-verb agreement?

1. Tricia,as well as all her colleagues, are being trained on new equipment.
2. Here comes your teachers.
3. That box of two dozen eggs need to be put in the refrigerator.
4. The excuse he gave for being late seems legitimate.

The correct one is 4.
1 should be "Tricia, as well as all her colleagues, /is/ being trained on new equipment" (Subject is Tricia, not her colleagues, and is therefore singular)
2 should be "Here /come/ your teachers"
3 should be "That box of two dozen eggs needs to be put in the refrigerator" (The subject is the box, not the eggs)

To determine which sentence illustrates subject-verb agreement, we need to identify the subject of each sentence and ensure that the verb agrees with it in terms of number (singular or plural).

1. "Tricia, as well as all her colleagues, are being trained on new equipment."
In this sentence, the subject is "Tricia," and the verb "are" does not agree with it. To correct the subject-verb agreement, it should be "Tricia, as well as all her colleagues, is being trained on new equipment."

2. "Here comes your teachers."
In this sentence, the subject is "teachers," and the verb "comes" agrees with it. This sentence demonstrates subject-verb agreement.

3. "That box of two dozen eggs needs to be put in the refrigerator."
In this sentence, the subject is "box," and the verb "need" does not agree with it. To correct the subject-verb agreement, it should be "That box of two dozen eggs needs to be put in the refrigerator."

4. "The excuse he gave for being late seems legitimate."
In this sentence, the subject is "excuse," and the verb "seems" agrees with it. This sentence demonstrates subject-verb agreement.

Therefore, the correct sentence that illustrates subject-verb agreement is sentence number 4: "The excuse he gave for being late seems legitimate."