Mr. Firman invited his friend, Mr. Nulty, to come over and have dinner with him and Mrs. Stoner. The maid fixed a big dinner for the three of them, and when they were ready for dessert, she brought a cake out for Mr. Nulty because it was his fifty-ninth birthday. The candles were lit and the lights were turned out so that he could blow out the candles in the dark. Mrs. Stoner then begins to clear the table of the food and dishes.

It says to rewrite the paragraph correcting the shifts in verb tense. I don't get it

Mr. Firman invited his friend, Mr. Nulty, to come over and have dinner with him and Mrs. Stoner. The maid fixed a big dinner for the three of them, and when they were ready for dessert, she brought a cake out for Mr. Nulty because it was his fifty-ninth birthday. The candles were lit and the lights were turned out so that he could blow out the candles in the dark. Mrs. Stoner then begins to clear the table of the food and dishes.

Look at the last sentence. It is NOT the same tense as the first sentence. In addition the tenses change from Active Voice to Passive Voice. So you need to change to all Active.

Mr. Firman invited his friend, Mr. Nulty, to come over and have dinner with him and Mrs. Stoner. The maid fixes a big dinner for the three of them, and when they are ready for dessert, she brings a cake out for Mr. Nulty because it is his fifty-ninth birthday. The candles are lit and the lights are turned out so that he can blow out the candles in the dark. Mrs. Stoner then begins to clear the table of the food and dishes.

To rewrite the paragraph and correct the shifts in verb tense, we need to ensure that all the verbs in the paragraph are consistent in terms of tense. Here's the revised paragraph:

Mr. Firman invites his friend, Mr. Nulty, to come over and have dinner with him and Mrs. Stoner. The maid fixes a big dinner for the three of them, and when they are ready for dessert, she brings a cake out for Mr. Nulty because it is his fifty-ninth birthday. The candles are lit and the lights are turned out so that he can blow out the candles in the dark. Mrs. Stoner then begins to clear the table of the food and dishes.