In William Shakespeare’s play Romeo and Juliet, Friar Laurence contributes to the tragic ending by:

1. Giving Romeo a sleeping potion
2. Telling no one of his advice to Juliet
3. Going to Mantua himself to speak to Romeo
4. Pretending to be Lord Capulet

4. Pretending to be Lord Capulet is not accurate. Friar Laurence does not pretend to be Lord Capulet in the play. The correct option is:

1. Giving Romeo a sleeping potion. Friar Laurence gives Romeo a potion that puts him into a deep sleep, causing miscommunication and ultimately leading to the tragic ending.

In William Shakespeare's play Romeo and Juliet, Friar Laurence contributes to the tragic ending by:

1. Giving Romeo a sleeping potion: Yes, one of the ways Friar Laurence contributes to the tragic ending is by giving Romeo a sleeping potion. He advises Juliet to take the potion to feign her own death and escape her unwanted marriage to Paris. However, Friar Laurence's plan fails when Romeo does not receive the message about the potion and believes Juliet is dead.

2. Telling no one of his advice to Juliet: Yes, Friar Laurence also contributes to the tragedy by keeping his plans a secret and not informing anyone about the advice he gives to Juliet. By doing so, he allows for miscommunication and confusion, which ultimately leads to the tragic events that unfold.

3. Going to Mantua himself to speak to Romeo: No, Friar Laurence going to Mantua to speak to Romeo does not directly contribute to the tragic ending. He goes to Mantua to be with Romeo, provide him with news, and make plans for the future. This action is not a direct factor in the tragic outcome.

4. Pretending to be Lord Capulet: No, there is no mention of Friar Laurence pretending to be Lord Capulet in the play. This action does not take place and therefore does not contribute to the tragic ending.

In William Shakespeare's play Romeo and Juliet, Friar Laurence contributes to the tragic ending by:

1. Giving Romeo a sleeping potion: This is correct. Friar Laurence's plan to give Romeo a sleeping potion, which would make him appear dead for a short period of time, is a crucial factor in the tragic ending. However, it is important to note that Friar Laurence's intention was to help Romeo and Juliet reunite rather than cause their demise.

2. Telling no one of his advice to Juliet: This is partially correct. While Friar Laurence does keep his plans a secret, he does so out of a desire to protect Romeo and Juliet's secret marriage and find a way to end the feud between their families. He does not anticipate the series of disastrous events that follow his decision to keep his advice concealed.

3. Going to Mantua himself to speak to Romeo: This is incorrect. Friar Laurence does not go to Mantua himself to speak to Romeo. Instead, he sends Friar John with a letter explaining his plan to Romeo, but unfortunately, the message does not reach Romeo in time.

4. Pretending to be Lord Capulet: This is incorrect. Friar Laurence does not pretend to be Lord Capulet in the play. He is a respected and trusted figure in Verona, primarily known for his knowledge of herbs and potions, and his role as a religious authority who marries Romeo and Juliet in secret.

So, the correct answer is:

- Giving Romeo a sleeping potion.