The past tense is downed.
Choose is not past tense, it's present tense. The past tense is chose.
Is can be used in the past tense if it's in its past tense form, which is was.
The past tense is undid.
past tense is dodged
Ought is already acceptable in past tense. 'Ought to be' is present tense, while 'Ought to have been' or 'Ought to have' is past tense.
The past tense is fell down.
The past tense is sat down.
The past tense is stepped down.
The past tense of "lie down" is "lay down."
The past tense of "slow down" is "slowed down."
The past tense of "lay down" is "laid down."
The past tense of "lie down" is "lay down", and the past participle is "lain down".
past tense
Felled is the past tense of fell, which means to knock or cut down.
he was He was walking down the street.
the past tense of am is was and the past tense of has is had
Yes it's the irregular past tense of lay. There's no rule with irregular verbs, you simply have to learn the past forms.