It is already in past tense, because it has the word built, which is in past tense. In present tense, it's, "You are building the boat very quickly."
This sentence is in the present tense.
The present tense of the sentence "She turns the light on" is "She turns the light on."
The tense for the sentence "I am speaking English" is present continuous tense.
Build is present tense. The past tense is built.
The verb in the sentence is in present tense.
The present perfect tense of build is:I/You/We/They have built.He/She/It has built.
That sentence is present tense. "Is" is a present tense linking verb.
Present tense.
The verbs will be in their present tense form. The sentence will be referring to something that is presently happening.
The form of the verb provides this information, although sometimes it needs to be clarified. There are some verbs (such as read) that use the same spelling for the present tense and the past tense. Example: He runs is the present tense. (He is running) He ran is the past tense. (He was running) He will run is the future tense. (He will be running)
You convert a sentence in the present tense to a sentence in the past tense by simply changing the verb form to the past tense. You converted a sentence in the present tense to a sentence in the past tense by simply changing the verb form to the past tense.