Another tip that I have for you is about the end of the verbs in the past. Here you are (extracted from esl about):
Group A
Voiceless sound: p, k, s, ch, sh, f, x, h - pronounce ED as "T". Example: ask - asked (t)
asked, baked, brushed, cooked, cracked, crashed, danced, dressed, dropped, escaped, finished, fixed, guessed, helped, hoped, joked, jumped, knocked, kissed, laughed, locked, looked, missed, packed, panicked, picked, pressed, pushed, pronounced, relaxed, relaxed, slipped, smoked, stopped, shopped, talked, typed, walked, washed, worked.
Group B
Voiced Sound: l, v, m, n, r, b, v, g, w, y, z and vowel sounds (diphthongs) - pronounce ED as "D". Example: allow - allowed (d)
advised, agreed, answered, appeared, arrived, believed, belonged, bored, burned, called, carried, changed, cleaned, closed, covered, cried, damaged, described, died, dried, earned, encouraged, enjoyed, entered, explained, explored, filled, followed, happened, interviewed, imagined, jailed, killed, listened, lived, loved, measured, moved, opened, planned, played, performed, pulled, realized, remembered, rained, repaired, saved, shared, shaved, showed, snowed, studied, tried, traveled, turned, used, welcomed, whispered, worried, yawned.
Group C
T or D pronounced as "ED" or "ID". Example: need - needed (id)
accepted, afforded, arrested, collected, contacted, counted, decided, defended, demanded, divided, ended, expanded, expected, exported, flooded, graduated, hated, hunted, included, invited, invented, landed, painted, planted, printed, presented, protected, provided, rented, repeated, reported, respected, rested, scolded, skated, started, shouted, treated, visited, waited, wanted, wasted.
Practice, practice, practice, and your pronunciation will get better, no doubt about it! See you!