A very safe tense. Take off the ending, add -aba or -ía, and you can be confident of the result. Only three verbs misbehave.
The accent does not move in any of them. Iba blends the two endings, and veía keeps the extra e that veo has in the present.
The point past is the less reliable tense. There is a group of irregular verbs there, mostly -go verbs but not all, and they all behave alike in three respects.
-e and -o from the -ar group, the rest from -er / -ir
Once you know the changed base, everything else follows the same shape.
Tuve and estuve are worth learning together. Note the accent is on the first syllable throughout, not the ending.
No estuve · ¿Dónde estuviste? · ¿Dónde estuvieron? · Tuve que ir
A practical concession. In conversation, if you cannot find the irregular form in time, the line past is regular and will get the meaning across.
Tuve que ir, or the regular tenía que ir
The two hook verbs, for comparison against the irregulars above.
hablé · habló · hablamos · hablaste · hablaron
comí · comió · comimos · comiste · comieron
In the informal you ending you can hear both the s and the t associated with informal you.
The whole approach to this group in one line: work through one verb properly, and for every other one all you need is the irregular base.
tuv-, estuv-, dij-, pud- and the endings are already known.